World No. 1 Novak Djokovic is looking forward to a new rivalry at the summit of men's tennis after losing a hard-fought French Open final against Spanish claycourt king Rafael Nadal.

The 25-year-old Serb insisted the sport's biggest matchup was still between 30-year-old Roger Federer, holder of a record 16 grand slam titles, and Nadal, who at 26, already has 11 majors topped by a record seven at the French Open. But he clearly singled out Nadal as his main foe.

"We are very young, and we played over 30 times against each other, and hopefully we can have many more battles in the next years," Djokovic said.

Five-time major winner Djokovic, who holds the Wimbledon, US Open and Australian Open titles, on Monday missed his chance of emulating Don Budge (1938) and Rod Laver (1962 and 1969) by holding all four grand slams at once. A disastrous double fault cost him a chance to stretch the Roland Garros final to five sets against Nadal after an overnight rain delay - only the second time in history that the final had to be fought in the third week.

"I think the sport is experiencing some really good times now," said Djokovic, who beat Federer in straight sets on Friday.

Happily married Federer believes he has a few more years of top-level competition left in him, including playing at the 2016 Olympics, even though he turns 31 in August and is busy looking after twin girls when not on court.

He holds six All England titles, just one short of the seven held by Pete Sampras.

"Obviously Federer and Nadal have still, I think, the biggest rivalry in the sport," Djokovic said.

"Because they have been at the top for so many years, they have been so dominant. I mean, I just joined that rivalry, I think, you know, just recently, couple years ago," he said.

"We're attracting a lot of attention to men's tennis because we have, you know, these two great players, and (Andy) Murray, myself, and we really have some great players, some charismatic players, a lot of personalities."

"This is good for tennis," said Djokovic, who kept his top world ranking.

Nadal himself paid tribute to his rivals for driving his desire to win.

"I feel very lucky to achieve all that I achieved until today," he said after his latest victory.

"I have great rivals."