Canadian Milos Raonic continued his hot play this year as he advanced to the second round of the Regions Morgan Keegan Championships on Wednesday night in Memphis.

The hard-hitter from Thornhill, Ont., fired 15 aces and won 84 per cent of his first serve points en route to a 6-2, 7-6(3) victory over Ernests Gulbis of Latvia.

Raonic, who on Sunday in San Jose became the first two-time winner on the ATP World Tour this year, improved his overall match record to 12-1 in 2012. The 21-year-old, seeded fourth in the tournament and ranked No. 35 in the world, will next face Ukrainian Sergiy Stakhovsky on Thursday.

In the upset of the night, defending champion Andy Roddick of the U.S. suffered his earliest exit in 12 career appearances at the event. Roddick, a three-time champion who defeated Raonic in last year's final, fell 7-6(8), 7-5 to Xavier Malisse of Belgium.

Elsewhere, top seeds Daniel Nestor of Toronto and Max Mirnyi of Belarus opened their doubles title defence with a 7-5, 6-2 victory over Kevin Anderson and Mark Knowles. Nestor and Mirnyi won 30 of their 31 first serve points and finished with 11 aces as they advanced to the quarter-finals in one hour and 11 minutes.