(Agencies)
Updated: 2007-11-13 09:32

SHANGHAI - Rafael Nadal's rivalry with Roger Federer is already the stuff of legend, but the Spaniard says their dominance of the sport could be under threat from a new generation of challengers.

Rafael Nadal's, seen here, rivalry with Roger Federer is already the stuff of legend, but the Spaniard says their dominance of the sport could be under threat from a new generation of challengers. [Agencies]

The world number two, who opened his Masters Cup campaign with a win on Sunday, predicted Novak Djokovic and Andy Murray would lead the charge for the top two rankings spots -- which have been unchanged since July 2005.

"For the last two years Roger has been at one level, I've been at another level, and the other players were all close," he said at the Masters Cup here.

"Right now Djokovic is having a very good season. He has a chance to be number one or number two. Murray is coming very well too.

"So next year there's going to be more players fighting to be number one and number two."

Still only 21, Nadal seems like a veteran with three French Open titles and an Open-era winning streak of 81 matches on clay.

Epic showdowns with Federer at Wimbledon and Rome rate among the classics, but Nadal said he was enjoying seeing the emergence of players he faced as a teenager.

"Right now the tour is in a very good position, very young players are coming. Djokovic, me, (Richard) Gasquet, (Tomas) Berdych, (Gael) Monfils, (Juan Martin) del Potro, Murray, a lot of players, very young players the same age as me," he said.

"So it's nice for the tennis, and it's nice for me because I played against these players when I was in juniors, when I was 14 years old."

However Nadal admitted there was still an enormous gulf between him and Federer despite narrowing the points gap this season.

"Well, this year I'm closer to him. But the difference is still 995 points. That's not very close," he smiled. "That's a lot of points."

Nadal conceded the first set to Gasquet in a slow start to his Masters Cup campaign on Sunday but soon hit his stride, eventually securing a convincing 3-6, 6-3, 6-4 win.

He admitted feeling nervous early on before returning to his snarling best, chasing down balls and pounding winners from all over the court.

"I improved later. I played more aggressively. I found some rhythm in the legs, in the movement," Nadal said.

"I improved a lot while the match was going on. For that reason, I finished the match playing more aggressive than the beginning."

Nadal is seeking his first Masters Cup title after pulling out injured in 2005 and losing to Federer in last year's semi-finals.

Defending champion Federer opens his quest for a fourth title against Fernando Gonzalez later on Monday.