Roger Federer and Rafael Nadal will square off for the 35th time in the Australian Open final on Sunday. In anticipation of their duel in Melbourne, we look back at the most significant match they ever played.

On May 15, 2006, the notoriously divided world of tennis found something that it could agree on: that the rivalry between Roger Federer and Rafael Nadal, after simmering for two years, had come to a boil over the course of a five-hour final at the Foro Italico in Rome.

More important, fans and media concurred, was that this clash of opposites was exactly what the sport needed.

Borg–McEnroe, Evert–Navratilova, Sampras–Agassi. Tennis, that metaphorical duel, is at its best when there’s a tug of war between two top players. If the crushing, captivating five-set duel that Federer and Nadal staged was any indication, the stylish Swiss and the swashbuckling Spaniard were about to carry the game into a new golden age.

For once, the prophecies proved correct and the optimism was justified. Eleven years later, we’re still living in the prosperous, golden era that Federer and Nadal kicked off that day. What no one could have known then, though, was that it would be the quality of their relationship, as much as the fierceness of their rivalry, that would put a unique, indelible stamp on the decade to come.

***

“This is a day I cannot forget,” said Rome tournament director and longtime player-agent Sergio Palmieri in a soft voice of awe, as he looked back on the 2006 final. “What really hit me was how big the respect was between the two guys. The intensity of that match was really unbelievable.”

The 2006 Rome final was the Big Bang of our current tennis universe, and to watch it now is to feel its particular hothouse intensity all over again. Here was one of those rare moments when the sport’s future seemed at stake.

The match was played on a bright, warm day in the Foro Italico’s old, intimate Campo Centrale. It was so intimate, in fact, that there wasn’t much room for Federer and Nadal to maneuver as they backed each other up with topspin blasts and slid past the doubles alleys to track them down. The playing surface was a tight rectangle, and the presence of the ever-excitable Italian fans a few feet away only heightened the tension of a match between the world’s top two players.

For his part, Nadal used every inch of clay available, and maybe a few inches that weren’t. Still a teenager, he was a rawer, spryer, more spontaneous and fearless version of the man we see now. This was the Rafa of the highlighter-green sleeveless shirt, the calf-length pirate pants, the shoulder-length hair. This was the Rafa who was happy to stand at the back of the court and run like mad all day. This was the Rafa who transformed every ball he hit into a flying topspin buzzsaw, grunted loudly during points and leaped high in celebration after them.

On the other side of the net, Federer was dressed in all white. If the colorful Nadal stood for the boldness of youth and a more physical future for tennis, the traditionally-attired Federer stood for the opposite. With his one-handed backhand, all-court savvy, serene demeanor and artistic racquet-work, Federer was the throwback who connected the modern power game with the grace and finesse of its past.

In 2006, the finest of his many fine seasons, the 25-year-old Federer would go 92–5, reach 16 of 17 finals and win three Grand Slam titles. To many, his success proved that style in tennis did matter; flawless technique led to flawless results. More than any other player, Federer had merged the aesthetic with the utilitarian. In the eyes of his fans, beauty, for the few hours when Federer was in full flight, really was truth. After watching him win Wimbledon in 2004, The Times of London sports columnist Simon Barnes wrote, “When Federer plays, he creates a strange illusion, that he is creating a spontaneous work of art for our particular delight.”

“I think the thing for me that is interesting was the fact that this Spanish lefty got under the skin of the great Federer. This has had the effect of separating the fans. You either had to like the Stones OR The Beatles, Led Zeppelin OR Deep Purple, and Roger OR Rafa. But both are amazing athletes, which meant the tennis was breathtaking.”—Pat Cash

The relative statures and opposing natures of Federer and Nadal in May 2006 helped create the exquisite tautness of the Rome final. This was a battle not just between tennis players, but between tennis philosophies. Did this Mallorcan muscleman really think he belonged on the same court as the Swiss maestro? Apparently so, to the dismay of traditionalists. Coming in, Nadal was 4–1 against Federer, and it was obvious that his heavy, lefty topspin was a potent weapon when aimed at the classicist’s one-handed backhand. Nadal had discovered Federer’s Kryptonite; he had found a flaw in the jewel. Of the five losses that Federer would suffer in 2006, four of them would come at the hands of Nadal.

“He doesn’t hit the ball flat and hard,” a flummoxed Federer said in 2004 after losing to a 17-year-old Rafa for the first time. “It’s more with a lot of spin, which makes the ball bounce, bounce high, and that’s a struggle I had today. I tried to get out of it, but I couldn’t.”

For the next two years, Federer and much of the tennis world faithfully waited for him to find his way out of Nadal’s trap. Ranked No. 1, Federer tried to pass off the defeats as part of the learning process. In April 2006, after losing to Nadal in another close final in Monte Carlo, Federer had maintained that he was a “step closer” to solving the Rafa riddle. Yet he also admitted that he couldn’t put his finger on why he was losing to him. “I also would like to be able to answer more clearly why it happened,” Federer said, “but I’ve got to change it next time. I’ve got to play aggressive.”

Federer lived up to his vow three weeks later in Rome. He came to the net 84 times and won 64 of those points. He controlled the rallies with his forehand rather than letting Nadal control them with his. He sent Rafa into the sideline walls with his sharp angles. He won the first set by playing a perfect 7–0 tiebreaker. In the fifth set, he led 4–1 and had two match points. In the deciding tiebreaker, he led 5–3.

Yet after all of that, Nadal ran away with the last four points and the title.

“I had a couple of match points, I pulled the trigger too early,” Federer said. “I definitely played some of the best attacking tennis on clay that I could play. But he defends so well and makes you doubt.”

It was that doubt, which Federer didn’t feel against anyone else, that made the difference. It wouldn’t be the last time that Federer pulled the trigger too early on a forehand against Rafa; over the years, the majority of Nadal’s wins over him would end with a Federer forehand miss.

Nadal, on the other hand, never had any doubt about what his strategy should be when he faced Federer. “You can’t even call it a tactic, it’s so simple,” he wrote in his autobiography, Rafa. “I play the shot that’s easier for me, and he plays the one that’s harder for him.”

“What sticks out is the deep respect these two have continued to hold for each other throughout the twists, turns and intensity of their rivalry. It was missing in top men's rivalries for a very long time beforehand. There's a gracefulness in the way Roger and Rafa approach their combat that encourages admiration of the men as much as the tennis they play against one another.”—Jim Courier

Just as important was the way that Nadal approached their matches. He was the first, and so far the only, opponent to use Federer’s otherworldly reputation against him. Credit, in part, must go to a brilliant bit of reverse psychology on the part of his uncle and coach, Toni Nadal.

“Toni,” Nadal has said, “has never ceased to remind me—and I know he is right—that Federer is more technically gifted than I am.”

Toni’s words freed Rafa from having to think of himself as better or worse than Federer, and freed him from the pressure of trying to measure up to him. When he played Federer, all the younger man could do, as he has said many times, was “try my best.” Even after Nadal had beaten Federer a dozen times, he didn’t let go of his humble mindset; Rafa continued to insist that Federer was “the best in the history.” Nadal believed it, but it also happened to be a useful, pressure-relieving way for him to view their rivalry.

In Rome, Federer felt something more than doubt. For the first time, he let his frustration with playing Nadal show. During the match he looked toward the player’s box and asked, “Everything all right, Toni?” Was he talking to his coach, Tony Roche, or his agent, Tony Godsick? No, Federer was lobbing a little sarcasm in the direction of Rafa’s uncle. Federer felt that Toni Nadal was illegally giving his nephew advice.

“He was coaching a little bit too much again today,” Federer said. “Yeah, I caught him in the act.”

The handshake between the two was as hurried and icy as the match had been long and hot. Later, Federer called Nadal’s game “one-dimensional.” The next day, Nadal said of Federer, “He has to learn to be a gentleman even when he loses.”

Were the two about to follow in the footsteps of tennis rivals past and turn their matchup into a blood feud? Many promoters hoped the answer was yes. As the Associated Press wrote during that year’s French Open, “It wouldn’t hurt the TV ratings or buzz factor if there were a bit of animosity—or at least a difference of opinion [between the two].”

“The most prominent rivalries are about where, when, and how often the greats face each other. What has been terrific about this rivalry is that their styles of play are as different as their personalities. In this regard, it is great for the sport and also great for the fans—their personality types grab different fans."—Paul Annacone

After Rome, Federer and Nadal each withdrew from the next tournament, in Hamburg. But they couldn’t avoid each other at the Laureus Sports Awards in Barcelona at the end of May. Federer was nominated for Sportsman of the Year, Nadal for Newcomer of the Year. Each won, and each found himself applauding for the other. Maybe it was these triumphs that softened the edge, but that moment marked the end of their early dissension and started their rivalry down a new track. “We sat at the same table with the Princess of Spain between us,” Federer said, “and noticed that it wasn’t such a big deal.”

Over the course of five hours in Rome, each man had earned the other’s respect. Nadal had always known how good Federer was; now Federer knew that Nadal wasn’t going anywhere. There was room, it seemed, for both of them at the top.

“Such respect,” wrote British tennis journalist Chris Bowers of Federer and Nadal in 2014, “coupled with a modesty that was in no way false, allowed the two men to develop a friendship that, if not quite on the level of bosom buddies, stands in marked contrast to several previous rivalries that included an element of personal dislike.”

Three years and many epic matches later, Federer himself would marvel at how far his relationship with Nadal had come.

“I’m surprised by the degree to which we get along,” Federer told The Sunday Times in 2009. “We’ve had a very intense rivalry, and you could say he has hurt my career and that I’ve hurt his career. But we’ve actually helped each other become the players we are today, and the rivalry has helped the game.”

"These two guys have fan bases that are incredible—the greatest thing about a rivalry is that people are rooting for both sides. They brought a rock-star element to tennis that transcended the sport.”—Brad Gilbert

In the years after Federer and Nadal buried the hatchet, the two men came together to create a series of classic matches. By the end of the decade, their names were as inextricably linked as Borg’s and McEnroe’s had been to an earlier generation.

Two months after Rome, Federer beat Nadal for the first time that year, in the Wimbledon final. Instead of an icy encounter at the net, the most memorable image from that day was the smiling hand slap they gave each other as they circled Centre Court with their trophies.

In the following two summers, they would stage even more memorable Wimbledon finals. In 2007, Federer won a glorious, sun-splashed five-setter; as he rolled on the turf in celebration, Nadal bowed his head on the sidelines in tears. In 2008, Rafa would put those tears behind him for good by winning an even better and more dramatic final as night closed in. At the net, as flashbulbs popped around the stadium, the two shook hands and bowed their heads toward each other in near-darkness.

Yet the most lasting image of all would come the following January at the Australian Open. There, Nadal again beat Federer in five long, brilliantly played sets. If Federer let his frustration show in Rome, he let it flow in Melbourne. “It’s killing me,” he said as he tried to give his runner-up speech, only to be overcome by tears.

When he retreated from the microphone, and Rafa walked back and threw his arm over Federer’s shoulder, the two were connected—physically and spiritually—in our minds forever.

That’s where they remain eight years later. Neither is No. 1 in the world anymore. Neither has won a major in three years—though that's about to change—and their slightly younger colleague, Novak Djokovic, has been the best player of this decade. Other rivalries have largely eclipsed Rafa vs. Roger in importance and frequency.

Yet there’s a reason why the idea of seeing them on the same court is enough to make a tennis fan feel like history is in the air. Federer vs. Nadal is elemental, mythical. From the start, it was about the younger man trying to catch and surpass the older man—a man who seemed to be unsurpassable, and in some ways always has been. The rivalry was about opposites on the court—the effortless Federer vs. the effort-full Nadal—and in the interview room. Where Federer has, rightly, never pretended to be anything less than a champion, Nadal, just as rightly, has never pretended to be anything more than a human.

Federer and Nadal came to embody so many opposing traits and world views between them—pride vs. stoicism, gracefulness vs. passion, matador vs. bull—that it was always hard to know where Djokovic would fit in with fans. No matter: Djokovic has consciously followed in their footsteps, both as a player and a well-spoken ambassador for the sport.

Eleven years after Rome, waiting for another installment of Federer vs. Nadal is a little like waiting for The Beatles to get back together in the 1970s. You knew then that music had moved on to more technically impressive things, but The Beatles were still the originals, the totems of youth and innocence.

For anyone who came of age during this golden decade of tennis, or who came back to the game because of it, Federer and Nadal play the same foundational role. They’re the ones who started it all, who, like Romulus and Remus, conjured magic from dusty Roman clay. Whatever their rankings, whatever ups and downs they’ve had, that magical spark will always be there when they walk onto a court together. The tennis world may still not be able to agree on much, but we can agree on them.