MONTE CARLO (AFP) - World number one Rafael Nadal finished with an ace on match point to seal his 300th career victory on clay and advance into the quarter-finals of the Monte Carlo Masters on Thursday.

He was joined in the last-eight by defending champion Novak Djokovic who eased past Spain's Pablo Carreno Busta 6-0, 6-1 and seven-time Wimbledon champion Roger Federer who spent just 57 minutes in going past Czech Lukas Rosol 6-4, 6-1 to next line up against ninth seed Jo-Wilfried Tsonga.

Nadal, the eight-time winner in Monte Carlo, became just the 11th man to crack 300 wins on clay - the last to do so was Spaniard Carlos Moya, who ended his career in 2007 with 337 victories.

The Spaniard said he felt an improvement in his play in his 6-1, 6-3 win over Italy's Andreas Seppi, with the victory taking him into another meeting with compatriot David Ferrer.

Spanish sixth seed Ferrer booked his place by beating Bulgarian number 12 Grigor Dimitrov 6-4, 6-2.

Nadal still has ground to cover on clay before approaching the all-time top winner on the surface - Argentine Guillermo Vilas compiled a record of 644-183 on the surface three decades ago.

"I did what I had to in order to get where I am," the top seed said of his third-round win.

"But playing David (Ferrer) is never easy. If you are not at the top of your game you will lose. I'm just glad to be in a quarter-final."

Nadal had a few spots of bother against Seppi, with the world number one forced to save five break points in the sixth game of the opening set for a 5-1 lead.

"At 4-1 I just stopped moving my legs, it was mental, not physical," he explained.

In the second set, Nadal dropped serve to love while leading 4-2. But he got it straight back for 5-3 and finished off the victory in 93 minutes.

Swiss fourth seed Federer, the record 17-time Grand Slam winner, came back from a break down in the first set before crushing his opponent to win an ATP-leading 26th match this season.

Frenchman Tsonga celebrated his 29th birthday with a win in controversial circumstances over flamboyant Italian Fabio Fognini, who went into meltdown in a 5-7, 6-3, 6-0 defeat.

The 10th seed won just four points in the final set, where he was jeered by fans.

"Today I felt a lot better than the first day, where my legs felt very heavy," said Tsonga. "I knew I could stay on the court for a long time.

"In the beginning he was better than I was physically, but I made him play each point and I didn't make any unforced errors."

Swiss Stanislas Wawrinka earned a free trip into the last eight when Spain's Nicolas Almagro retired before their third-round match with a foot injury.

Australian Open winner Wawrinka, seeded third, will Friday face off against Canadian eighth seed Milos Raonic, who beat 11th-seeded Spaniard Tommy Robredo 6-4, 6-3.

Wawrinka has beaten Raonic in both of their previous meetings, in 2012 and 2013 on hardcourt.