Tennis days don’t get much more thrilling than August 13, 2016. That evening, in the women’s gold-medal match at the Rio Olympics, Monica Puig upset Angelique Kerber to earn Puerto Rico its first gold in any event. Just as compelling, though, was what happened during the warm-up act. That’s where, in the second men’s semifinal, Juan Martin del Potro beat Rafael Nadal, 5-7, 6-4, 7-6 (5), in three hours and eight minutes.

Del Potro and Nadal were both making comebacks, and neither could have expected to be in this position. The Argentine had been away for two years with wrist injuries, while Nadal, suffering from his own forearm problem, had decided to play in Rio only at the last minute. Now they stood face to face on the baseline and produced what may have been the best sustained, shot-for-shot co-performance of the season. On the line was a chance to go for Olympic gold, something that neither of them would get to do for another four years, if ever. You could feel what that meant to them in every swing of their racquets, and you could hear it in the excitement that they generated from the crowd, which was one of the noisiest of the year.

Here’s a look at the 21-minute highlight clip above.

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—Nadal vs. Del Potro is a rivalry that has never become as heated or consequential as it should have, because of the injuries that have kept both men on the sidelines over the years. Back in 2009, Delpo won three straight meetings with Rafa; but before this match in Rio, they had faced each other just twice since 2011. They were due for a good one.

Nadal was as focused and fired up as always; he moved with abnormal dispatch between points. As for Delpo, this was the week when he went from 2016‘s feel-good story to a legitimate big-match threat again. He started the tournament with a win over top seed Novak Djokovic, in a match that was nearly as good as this one. And despite having played multiple times on multiple days, he finished the tournament by nearly pushing Andy Murray to a fifth set in the gold-medal match. Del Potro, who would lead Argentina to its first Davis Cup title in November, saved his best for his country in 2016.

—There was no easing into this one; it was a war from the start. By the time the long first game was over, both guys were at full throttle. Nadal played closer to the baseline than normal, and, as I mentioned in the recap of his U.S. Open match against Lucas Pouille, his backhand was grooved. In the first set, Rafa hit six backhand winners, and just two from the forehand side.

Still, in a sign of things to come, it’s Delpo who got in the last shot, and the last roar, in the opening game. He won it with a rocket forehand winner, and a well-timed grunt. As we’ll see, these aren’t just two of tennis’ greatest players— they’re two of its most accomplished showmen.

—For the first three or four months of his comeback, Delpo mostly sliced or blocked his backhand. By this point, he could put a little muscle behind it, and he even snapped off a couple of winners. But as he did for most of the season, the Argentine leaned heavily on his serve and forehand. He had 11 aces, and when he needed to, he found a way to run around his backhand and hit a forehand. Being so far out of position, he knew he needed to do damage with the shot, and most of the time he did. That skill, borne of necessity, is what made Delpo the equivalent of a Top 5 player this season. It may earn him a Grand Slam title in 2017.

—The dynamic of the rallies changed markedly at the start of the second set. Del Potro, with his back to the wall, started pummeling his forehand. At the same time, Nadal, one set from a chance to play for his second singles gold medal, took a step back and began slicing the backhands that he had been hitting so confidently in the first set.

—From there, through a classic 85-minute third set, the two men tried to wrest control of the baseline from each other. Del Potro seemed to be the stronger force, and he finally gained the upper hand by breaking at 4-4. But Nadal broke back at love, and juiced the crowd with a series of stutter-step fist pumps that nearly took him from the net to the baseline; he does them so quickly, it looks like the tape has been sped up. When he went up 6-5, Rafa looked ready to finish it, but Delpo stopped the bleeding, holding at love, and went up 3-0 in the deciding tiebreaker. Nadal, naturally, came roaring back to 5-6.

Finally, after all of those rapid-fire, whiplash-inducing momentum swings, Rafa did the same thing he’d do at 6-6 in the deciding tiebreaker against Pouille at the Open a month later. He worked himself into position for a gimme forehand, and missed it. This time, with Delpo running the other way and dead in the water, Nadal sent the ball over the sideline. Delpo’s reaction is equal parts joy and disbelief. All he could do was get down on the court and kiss the dot on the “I” in Rio. He had earned it.

“It was just amazing for me,” Del Potro said through tears.

“I did my best,” Nadal said, “It was a great match, full of emotion and played to a high level ... I fought, and with great spirit.”

It’s a spirit that only comes to a tennis court once every four years, and that may not be such a bad thing; the Olympics are nerve-racking. But the emotion of that match, and that day, will be with us for a while.