Soaring Serb Novak Djokovic secured a berth seeded Roger Federer lost Thursday at the $2.43 million Rogers Cup, an ATP Masters and U.S. Open Series event.

The world No. 1 Djokovic improved to 52-1 in his last 53 matches, including a 50-1 mark this season, by handling Croat Marin Cilic 7-5, 6-2 at Uniprix Stadium. Djokovic is a perfect 26-0 on hardcourts this year.

Djokovic, who captured the former Canadian Open in Montreal back in 2007, secured his first Wimbledon title last month and has already won eight titles on the ATP circuit this season.

Federer was upstaged by 13th-seeded Frenchman Jo-Wilfried Tsonga, 7-6 (7-3), 4-6, 6-1 under the lights. Unfortunately for Federer, it was a familiar result as he blew a two-set lead to Tsonga in the quarterfinals at Wimbledon a month ago.

The French Open runner-up Federer was last year's Rogers Cup runner-up to British star Andy Murray, in Toronto. The former world No. 1 and 16-time Grand Slam champion Federer, who turned 30 here on Monday, captured this Canadian event in 2004 and 2006 and was also a runner-up in 2007.

Tsonga moved into a quarterfinal matchup against No. 8 seed Nicolas Almagro of Spain. He topped 10th seed Richard Gasquet of France, 7-6 (7-5), 6-3.

Another Frenchman, fifth seed Gael Monfils, advanced by beating 12th seed Viktor Troicki of Serbia, 3-6, 7-6 (7-0), 7-6 (7-5). Monfils, who is fresh off his runner-up finish in Washington, D.C. last week, will next face Djokovic.

American Mardy Fish, the sixth seed, beat Latvia's Ernests Gulbis, 4-6, 6-3, 6-4.

Seventh-seeded 6-foot-5 Czech Tomas Berdych moved on with a 6-3, 7-6 (7-2) victory over 6-foot-10 Croat Ivo Karlovic. The two sluggers combined for 22 aces, including 12 from the Croatian loser.

Also advancing to the round of eight was 14th-seeded Swiss Stanislas Wawrinka, a 6-4, 4-6, 6-4 victor against tall South African Kevin Anderson, and Serb Janko Tipsarevic, who dismissed Croat Ivan Dodig 6-1, 6-4 on Day 4. Dodig stunned the great Rafael Nadal here on Wednesday.

Fish plays Wawrinka in the quarterfinals, while Berdych tangles with Tipsarevic.

The 2011 Rogers Cup titlist will pocket $450,000.