Updated

American Sam Querrey and two-time champion Xavier Malisse were each opening-round winners Monday at the Delray Beach International Tennis Championships.

Querrey, seeded third in this hardcourt event, earned a 6-2, 2-2 decision over Houston resident Michael Russell when the 34-year-old retired due to a leg injury in the nightcap at Delray Beach Tennis Center.

The eighth-seeded Malisse, meanwhile, blew past Colombian Alejandro Falla 6-3, 6-3 in just 75 minutes.

Malisse owns three career titles on the ATP World Tour, with two of them coming at this event, in 2005 and 2007. The five-time Delray Beach finalist was also a runner-up here in 1999, 2001 and 2006.

Fifth-seeded Alexander Dolgopolov was an upset victim in his first-round bout, however, with Croat Ivan Dodig breaking the Ukranian four times en route to a swift 6-3, 6-3 triumph that took under an hour.

Also on Monday, Russian Evgeny Donskoy beat Belgian Steve Darcis 7-6 (7-5), 6-3.

The top seeds this week are towering American John Isner and oft-injured German Tommy Haas, who titled here back in 2006.

South African Kevin Anderson beat Aussie Marinko Matosevic in last year's Delray Beach final.

The 2013 champion will pocket $78,000.