Nadal wins; Federer ousts Wawrinka

Of all the tournaments staged since ATP rankings began in 1973, Montreal marks the first that the world's top eight have fought their way to the quarterfinals of the same event.

Friday's high quality line-up will include players from eight different countries, four past champions and four grand slam winners.

Among them, only American world number five Andy Roddick has not claimed multiple titles this season.

Joining Federer and Roddick are world number two Rafael Nadal of Spain, Briton Andy Murray (3), Serbia's Novak Djokovic (4), Argentina's Juan Martin Del Potro (6), Jo-Wilfried Tsonga of France (7) and Russian Nikolai Davydenko (8).

Big-hitting Tsonga stands in the way of a semifinal berth for Federer, the Frenchman advancing with a 6-3, 6-3 win over compatriot Giles Simon.

Defending champion Nadal gave his knees a proper work-out in an energetic 6-3, 6-2 win over Germany's Philipp Petzschne.

Nadal can expect a much sterner test against Del Potro. The Argentine did it tough in his third-round match with Victor Hanescu of Romania, however, coming back from a set down to win 3-6, 6-3, 6-4.

Murray's hardcourt campaign moved into top gear with a 6-1, 6-3 win over resurgent Juan Carlos Ferrero, denying the Spaniard revenge for his quarter-final defeat at Wimbledon.

Playing his first event since falling to Roddick in the Wimbledon semifinals, Murray knocked the last bit of rust off his game to blast past Ferrero in just 77 minutes.

Murray next meets Davydenko, a 7-6, 7-5 winner over Chile's Fernando Gonzalez.

Roddick was left drained after his two hour and 36 minute defeat of feisty Spaniard Fernando Verdasco 7-6, 4-6, 7-6. The win set the American up for quarterfinal showdown with 2007 winner Djokovic, who beat Russian Mikhail Youzhny 6-3, 6-4.

Sisters ousted
Kim Clijsters' brilliant comeback continued at the Cincinnati Open with a 6-4, 4-6, 6-2 win over French Open champion Svetlana Kuznetsova on Thursday, but the Williams sisters both fell at the third-round hurdle.

Second seed Serena, struggling with a virus, lost 7-5, 6-4 to Austria's Sybille Bammer while in-form Italian Flavia Pennetta ended the hopes of third seed Venus with a 7-6, 6-4 victory.

Top seed Dinara Safina will be Clijsters' next opponent after she easily beat Peng Shuai of China 6-3, 6-4.

Pennetta will play unseeded Daniela Hantuchova after the Slovakian beat seventh seed Vera Zvonareva of Russia 7-6, 0-6, 7-6 in a see-sawing battle lasting two hours and 50 minutes.