MONTREAL: Roger Federer captured his 21st consecutive match win Thursday as he booked a quarter-final berth at the Montreal Masters and stayed on course for a finals showdown with Rafael Nadal.

Top-seeded Federer avenged a spring loss to fellow Swiss Stanislas Wawrinka with a 6-3, 7-6 (7/5) victory.

Second seed Nadal, playing this week for the first time since May 31 after resting his injured knees, gave his fragile confidence a huge boost with a 6-3, 6-2 defeat of German Philipp Petzschner.

The two led an historic parade of the top eight seeds into the into the quarters of the three million-dollar tournament - the first time since the rankings began in 1973 that the top eight players in the world have all reached the quarters at the same ATP event.

"It's not just the top eight seeds, it's the top eight players in the world," Federer said. "It's a special occasion. It shows that the top guys are really consistent at the big events. It's nice it finally happened."

Wawrinka, who played alongside Federer to win the Beijing Olympic doubles gold medal, had beaten his celebrated compatriot in the third round at Monte Carlo in April.

Wawrinka made Federer work for this one, saving four match points in the tiebreaker before missing a low volley at the net to exit after one and three-quarters hours.

Federer will next play Frenchman and Swiss resident Jo-Wilfried Tsonga, the seventh seed who beat compatriot Gilles Simon 6-3, 6-3.

"It was a tense match, you can never tell until it's over," said Federer, who has won his last three tournaments dating to May in Madrid. "Stan was serving really well. We played at a high level."

After claiming the first set with a forehand to the corner, Federer had trouble closing out the victory a set later. A 5-1 lead in the tiebreaker almost went for nought as Wawrinka fought back at the end.

"It was a very equal match," Federer said. "Stan had chances and played very well. But I served well when I needed to. I'm pleased to go through."

Federer beat Tsonga in their only meeting at Madrid, 2008.

Nadal showed some signs of nerves with a double-fault on his first match point, but fired home a winner on his second try.

"I'm very happy because I am in the quarter-finals. It's more than I expected when I came here," said Nadal, who caught a break when David Ferrer retired injured in the first set of their match on Wednesday. "So with one match and a half I have right now, I expect to be ready for tomorrow.

"The movement was a little bit better," he added. "I need more matches to get the rhythm."

Nadal will face Argentinian sixth seed Juan Martin Del Potro, who rallied to beat Victor Hanescu of Romania 3-6, 6-3, 6-4.

Third seed Andy Murray stayed in touch with his dream of seizing the world number two ranking from Nadal, stopping Juan Carlos Ferrero 6-1, 6-3.

Murray needs to reach the semi-finals, and also hope that defending champion Nadal does not progress into the final four.

Murray has now won all three of his matches with former number one Ferrero, beating the 29-year-old Spaniard on grass this summer at Queen's and Wimbledon. Victory took 77 minutes as the Scot never faced a break point.

"I played better and better as the match went on. If you can get a good start in all your matches it's going to make a big difference to whether you win or lose."

Murray will play eighth-seeded Russian Nikolay Davydenko, a 7-6 (7/2), 7-5 winner over Chile's Fernando Gonzalez.

Serbia's Novak Djokovic, seeded fourth, reached the last eight with a 6-3, 6-4 victory over Russian Mikhail Youzhny.

Djokovic won this event two years ago in Montreal, while Nadal won last year in Toronto as the event alternates between the cities.

Andy Roddick, seeded fifth, came good after Fernando Verdasco saved two match points, with the American three-time Wimbledon finalist defeating the tenth-seeded Spaniard 7-6 (7/2), 4-6, 7-6 (7/5).

"He was just crushing any ball, I was just trying to kind of fight him off for as long as I could," said Roddick. "That ended up being enough."

Roddick will next meet Djokovic after winning their last two meetings, including January's Australian Open quarter-finals.