Novak Djokovic is the new Wimbledon champion, simultaneously relieved and ecstatic to hold his nerve long enough in seeing off the defending champion Rafael Nadal 6-4, 6-1, 1-6, 6-3 in a final of spectacularly fluctuating quality.

The Serb took nearly two and a half hours to inflict the first defeat on Nadal here in four years and 20 matches. It might be the start of a new era, although the Spaniard will not step aside without a fight.

It was not the old Rafa and nor was it always the new Novak, the one who had beaten the Spaniard in four finals this year and who has taken the No1 ranking off him, breaking the seven-year hegemony at the top of Nadal and Roger Federer.

"It is the best day of my life," Djokovic said. "This is the tournament I always dreamed of winning. I think I am still sleeping, still dreaming. When you're playing the best player in the world ... I had to be on top of my game. I played probably my best match on grass courts ever."

Nadal started as he finished against Andy Murray in the semi-final, but the Serb ripped in a first-set ace to calm his charge. Then they just thumped away at each other – much as heavyweight boxers used to do. And one of the combatants in this final, the champion, was carrying a foot injury of which we have heard little since he had it wrapped publicly in his win over Mardy Fish four days ago.

The margin for error was cut, sliced and top-spun to the minimum as both players flirted with the net and the whitewash. Murray had success in the first set on Friday by working Nadal over on the backhand and Djokovic stuck with that strategy, forcing him wide to keep him away from his rasping forehand.

"You're a genius, Rafa, a genius," a fan shouted as Nadal produced a curling bit of cross-court magic at 3-3. There was a rare sign of tentativeness from Djokovic when his sliced drop shot trickled meekly into the bottom of the net as Nadal held at 4-4 but generally the intensity was high, the concentration complete.

So close were they that chances to break eluded both – until the 10th game. Ahead in the serving cycle, with nothing to lose, Djokovic attacked Nadal's serve mercilessly and when the champion chose to go round on his forehand, he was tight on the shot and netted for break point. Under far less pressure, he pushed another forehand wide and Djokovic was a set up after 42 minutes.

Djokovic looked the more convincing early in the second set. Nadal horribly messed up a smash and his length was awry on his ground strokes, but he still had the crowd, who gasped in disappointment when he gave up another two break points with a netted backhand at 0-1. But when Djokovic brilliantly wrong-footed him at the net with a dink that had him twisting in vain to retrieve, the court erupted.

The tennis reached sublime heights in the third game, as they traded one quality shot after another before Djokovic closed it out with an ace to go 3-0 up, and Nadal was struggling to stay in touch.

But he had served well from the start and a couple of aces, a miss-hit smash by Djokovic and a forehand that clipped the net hauled him back to 3-1.

Another outstanding exchange of angled shots, dipping ground strokes and a backhand smash ended with Nadal netting to give up another break point, and Djokovic duly broke him to go 5-1 up.

The Serb served the set out to love and Nadal was faced with the challenging of coming back from 2-0 down for the fourth time in his career. The last time he was in this much trouble was in Paris, where he came back from 2-1 down at the start of defending the French Open title. Now, on grass, against the player officially ranked on top in the world, he faced a far bigger mountain.

Finally, Nadal got a break, as Djokovic came down from Olympus in the second game of the third set and the Mallorcan had something to work with at 2-0 after an hour and 25 minutes.

When Nadal served to love again to go 4-1 up, the mood was with the title-holder. When Djokovic double-faulted in the first deuce game of the match to hand Nadal a 5-1 lead, and Nadal held to love for the third time in the set for 6-1, the final had been thrown wide open again after an hour and 44 minutes.

At 4.09pm one section of the roof was eased back to lighten the gathering gloom, and the little cloud that had followed Djokovic switched to Nadal when he belted a forehand into the middle of the net to go 2-0 down. In a twinkling, it was the Serb's final to lose.

When Nadal double-faulted for the first time and hit long to drop serve, Djokovic was left to serve for the match at 5-3 and so happy to see Nadal's last shot go long.