Ninth-seeded Kei Nishikori advanced with a hard-earned victory, while Janko Tipsarevic was an upset victim in Monday's first-round play at the $2.887 million Rogers Cup tennis event.

Nishikori overcame a slow start to best Canadian Peter Polansky by a 4-6, 6-4, 6-2 score on the hardcourts at this Masters 1000 tournament. The 16th-seeded Tipsarevic, however, was handled in just one hour and 20 minutes by Uzbekistan's Denis Istomin in a 6-4, 6-3 decision.

Elsewhere, Latvian Ernests Gulbis got past Spanish left-hander Feliciano Lopez 7-6 (7-4), 6-4, German Florian Mayer overcame Aussie Bernard Tomic 5-7, 6-3, 6-3, and Italian Andreas Seppi snuck past big-serving Czech Lukas Rosol 6-4, 4-6, 7-6 (7-4) at Stade Uniprix.

Also advancing on Day 1 were Frenchman Benoit Paire, Spaniard Pablo Andujar, Aussie qualifier Marinko Matosevic, Slovak Martin Klizan, Canadian Jesse Levine and Croat Ivan Dodig, who will meet last week's Washington, D.C., champion Juan Martin del Potro in the round of 32.

World No. 1 Novak Djokovic is the reigning two-time champion at this event and also claimed the title here in 2007. The Serbian stat beat Richard Gasquet in last year's final in Toronto, as this tournament shifts between Montreal and Toronto each year.

Djokovic and two-time Rogers Cup winner Andy Murray are this week's top seeds, while former No. 1 and another two-time champ, Rafael Nadal, is seeded fourth. Djokovic is the reigning Australian Open champion, while Murray holds the Wimbledon and U.S. Open titles and Nadal is the reigning French Open champ.

The Serbian star Djokovic will face Mayer in the second round.

This week's big winner will earn $547,300.