Djokovic beat the top-ranked Nadal 6-4, 6-4 in the Italian Open final Sunday to stretch his unbeaten start this year to 37 matches.
Djokovic trails only John McEnroe's 42-0 start in 1984. Overall, the Serb has won 39 consecutive matches stretching to Serbia's Davis Cup triumph in December, sixth best in the Open era, seven behind Guillermo Vilas' record set in 1977.
"It's an incredible honor to be a part of tennis history in some way and part of an elite group of players -- Federer, Nadal, McEnroe, [Ivan] Lendl, guys who were winning so many in a row," Djokovic said. "I don't know how much good it brings to tennis, but it's good that someone else is able to win other than just Federer and Nadal. It makes it more interesting."
The second-ranked Djokovic has beaten Nadal in all four finals they've played this year and defeated the Spaniard for the first time on clay last week in the Madrid Open final.
This win makes Djokovic the first player to beat Nadal on clay twice in the same year, a feat that comes exactly a week before the French Open starts.
"I'm just most happy about the game I have this year on clay -- the way I'm striking the ball and the way I'm so self-confident," Djokovic said. "I always knew I could beat the top players, but now I have the confidence to do it."
Djokovic's edge over Nadal could enable him to overtake his rival for the No. 1 ranking the week after the French Open.
"He's doing amazing things. Every match he's very tough mentally and physically," Nadal said. "I'm doing everything I can. I can't ask myself anymore now. I'm doing very well but one player is doing better than me. I am waiting every week to try solutions, so let's see."
Nadal said it's "impossible" for Djokovic's streak to go on forever.
"I have to wait for my moment to win and I know that," the Spaniard said.
Also Sunday, Maria Sharapova stormed to a 6-2, 6-4 victory over Sam Stosur in the woman's final for the biggest clay-court title of her career.
After a three-hour rain delay, the seventh-seeded Sharapova won the opening four games, then cruised from there to follow up her victory over top-ranked Caroline Wozniacki in the semifinals.
Sharapova is a three-time Grand Slam winner and Roland Garros remains the only major title she hasn't won. She'll now be among the favorites in Paris.
"This is just the beginning of many things to come. This is just the start of everything," Sharapova said during the trophy presentation.
Nadal had won this tournament five of the past six years and entered the final with a 31-1 career record in Rome. His only previous loss came to countryman Juan Carlos Ferrero in his opening round three years ago.
Djokovic attributed his win in Madrid partly to the altitude and faster conditions there. The conditions at the Foro Italico are more similar to those in Paris, perhaps making this victory more meaningful.
"Whatever the conditions I needed to step into the court and take chances and be aggressive," said Djokovic, who also won this title in 2008. "That's really the only way against Nadal on clay."
Djokovic also had to recover from a three-hour semifinal win over Andy Murray that ended near midnight Saturday. Fortunately for Djokovic, the rain delay before the woman's final gave him more time to rest.
"Everything is possible. That's the explanation," Djokovic said. "If you believe you can recover, if you do the job well with the team around you and try to focus on your goal and physically be ready. ... We did the job great. Today I was able to get the maximum of my abilities on the court."
Despite the delay, nearly all of the 10,500 ticket holders were on hand for the Djokovic-Nadal match, and with Italy located geographically in between Spain and Serbia both players received about equal support.
While Nadal was using more loopy topspin shots to keep the ball in the court, Djokovic flattened his shots out more often, skimming balls just over the top of the net.
Djokovic also stepped into the court more, while Nadal mostly stayed a good distance behind the baseline.
"I was happy with the way I [played] today. I didn't hit the ball [badly] but it seems like he's always in a better position," Nadal said. "I played more aggressive than one week ago. I didn't play all defensive like in Madrid."
At one point in the second set, Nadal began hitting high balls, almost like the moon balls seen on the women's tour years ago.
"I tried for a moment, that's true," Nadal said. "I lost in Madrid so I tried different things today. ... I have many things [to try] next time."
After trading breaks early in the second set, Djokovic began screaming to himself and pumping himself up after each winner as the match drew closer to the end. He also had to stretch his aching muscles in between points.
With rain drops beginning to fall again, Djokovic closed the match out with a break after a Nadal netcord put him in control of his fourth match point, then fell to the clay on his back and sprayed champagne on the court after the trophy presentation.
"I will definitely not touch the racket for the next four days," Djokovic said. "Rest is very important right now and then getting ready for Roland Garros."