MONTREAL (AFP) - Rafael Nadal made an encouraging start to the summer hard-court campaign as the Spaniard recovered to defeat Sergiy Stakhovsky 7-6 (7/4), 6-3 on Wednesday on another day of weather trouble at the ATP Montreal Masters.

The seventh seed had to wait for two hours before his match at the Uniprix stadium could begin after a morning rain shower was followed by a towel-drying effort and repairs to bubbles on the rubberised surface.

But once down to business, Nadal made the most of his opening contest on the cement, winning the first set in a tiebreaker and sweeping the second to reach the third round and a date with Mikhail Youzhny, who beat French ninth seed Gilles Simon 6-1, 6-4.

Nadal is playing Canada for the first time since winning his third title here in 2013. The world No. 9 improved to 40-12 on the season.

Japanese fourth seed Kei Nishikori, winner at the weekend of the Washington title and now ranked fourth on the ATP, started 6-3, 6-3 over Spain's Pablo Andujar in 70 minutes, winning his 50th match at the Masters 1000 level.

Nishikori made a successful comeback last week after a long-running thigh injury and said that his current fitness is good.

"I've been feeling pretty good. After winning the title, you have to feel good. My tennis is getting better," he said. "I didn't start quite well, but it was windy. We had a little wait, so it wasn't easy in the beginning.

But after a couple for games I was playing well, concentrating well, too. I'm very happy with my tennis today."

American Jack Sock sprang an upset on troubled 14th seed Grigor Dimitrov, who went down 5-7, 7-6 (7/5), 7-5.

Over recent weeks, the Bulgarian once tipped as a future Roger Federer lost both his Australian coach Roger Rasheed and Russian girlfriend Maria Sharapova.