KEY BISCAYNE, Fla. -- While most of his colleagues were enjoying some downtime at their homes scattered around the world last December, Novak Djokovic was still grinding.
He led Serbia to its first Davis Cup championship, over France, but after taking only six days off he began training for the 2011 season. Djokovic came flying out of the box, won the Australian Open and stayed white-hot for three months, running off to one of the greatest starts in tennis history -- he carried a 23-0 record all the way into the Sony Ericsson Open final.
On Sunday a weary Djokovic finally, perhaps inevitably, crashed and burned. In the first set, that is. Breathing heavily, the cumulative exhaustion evident in his body language, the 23-year-old was knocked around by the world No. 1, Rafael Nadal, holder of three of the four majors.
But then the player whose heart, when strained by adverse conditions, had been questioned for years, slowly, slowly wore down the toughest player we have seen in generations. Djokovic somehow summoned the will -- and the breathtaking skill -- to beat Nadal 4-6, 6-3, 7-6 (4).
Call Djokovic "Miami Vise."
After converting his third match point at the 3-hour, 21-minute mark, after throwing off his hat and hugging Rafa at the net, Djokovic pounded his heart with his fist as he looked to his box.
"It was one of the best finals I ever played in my life," Djokovic told the crowd afterward. "It's incredible to beat the No. 1 player of the world in a tiebreaker."
That sound you just heard was the shifting of the tectonic plates of tennis. Djokovic, technically the No. 2-ranked player in the world, has now beaten Nadal twice in two weeks and Roger Federer three times this young season. While Nadal was already shirtless and head down on his changeover chair, Djokovic had enough energy to jump earnestly for joy.
"It was very high level of tennis today that everybody enjoyed, even us playing," Djokovic said. "Up to the last stroke, we really didn't know which way it was going to go. Each point, each game that we played in the third set was very close.
"Really fortunate to get through this match. For these matches, you really play the sport. It's an incredible achievement, so I am very proud of this performance."
If this is the future of men's tennis, we'll take some more. They have now met 25 times; while Nadal still holds a 16-9 edge, Djokovic now has won nine of their 14 hard-court encounters.
This was a special match, the kind you might want to frame and remember. As the match hurtled into its third hour, the two started playing better and better, displaying the ethereal, sharply angled tennis that, going forward, promises to thrill us.
Afterward, Rafa catalogued his issues.
"Nothing left in my body right now. I was a little more tired than usual during this match. That's the sport. I love these kind of matches, for sure. I love to win, not lose. My serve didn't help me today.
"It was really close, especially at 6-5, 15-30. But I feel I did not play as well as some other moments in this tournament. He seemed less tired than before. Easiest thing to say: He's a very good tennis player."
Before the Indian Wells final, Djokovic had never, ever beaten Nadal in a tournament final. Now he's done it twice. Before this final, Djokovic had lost five of six tiebreakers to Rafa. This time, he took Nadal's best shot(s) and applied so much pressure it was the Spaniard who wilted; a double fault at 2-all might have been the pivotal point.
Djokovic is now 24-0 for the year and has won four titles. He's one win from equaling Ivan Lendl's blazing 25-0 start in 1986. Moreover, he has significantly altered the chemistry of the Big Three. Djokovic was only 4-8 in matches against top-10 players last season. This year, he's a remarkable 8-0.
He is the first man to win Indian Wells and Miami back to back since Federer did it in 2006.
We saw this marquee matchup two weeks ago in Indian Wells, when Djokovic beat Nadal in a three-set final. Coming in, Nadal said, he needed to be more aggressive, particularly on Djokovic's serve -- which he had held successfully 40 of 40 times. In the third game, Nadal put his plan into action by breaking Djokovic with a thunderous backhand winner.
When Nadal, leading 2-1, weathered three break points you sensed that Djokovic had finally run into the wall. Nadal again broke Djokovic in his next service game -- when a tired-looking forehand floated wide -- and you knew it for sure.
Djokovic rallied, though, breaking back and drawing to within two points of a 5-all. But when a forehand service return found the net and another short, makeable forehand followed it, Rafa had escaped with the first set. The difference: Djokovic had 19 unforced errors in the frame, nine more than Nadal.
After breaking Nadal to take a 2-0 lead in the second set, Djokovic lost it. Nadal had just scored a break point when Djokovic missed a short backhand, and the Serb cracked his racket, hard, on the court. The jolt served him well, because Djokovic won the next three points and came away with the 8-minute-plus game. He finished the second set with a 125 mph ace that brought the sold-out house to its feet.
The third set was terrific, often sending the raucous crowd into convulsions. The drama of the tiebreaker was as good as it gets in this game.
"You have to believe on the court," Djokovic said. "In the end, it's mental. In these moments, against a great champion like Rafa, you have to believe. It's all about stepping in and taking your chances. I always believed, but it's a process of learning."
And now, Djokovic and Nadal will towel off after playing a dozen matches in the United States in a little over three weeks. Nadal will fly back to his island home in Spain and Djokovic will retreat to beautiful Monte Carlo. After a few days of very little tennis, they will get back to the business of preparing for the clay-court season, where Nadal's history and skill set make him the favorite when they, inevitably, meet again.
"It's the best four months of my life," Djokovic said, "but it's only the start of the season. It's a little early to talk about getting the top spot in the rankings. If I want to have that shot at the No. 1 ranking, I'll have to play consistently.
"We all know that clay is [Rafa's] favorite surface. But these wins give me great confidence. This streak is incredible that I have. Right now, the rest is something I need very much. It's been a very successful four months, but an exhausting four months. Clay, where I didn't have great success last year, is my chance to get more success."
Greg Garber is a senior writer for ESPN.com.