Murray, Nadal advance

Andy Murray took care of some unfinished business as the second seed advanced to the third round of the ATP Tour's Montreal Masters on Wednesday with a 6-4, 7-5 win over Tommy Robredo.

The Scot ended the match, which was postponed because of heavy rain Tuesday, by executing a drop shot which bounced on the top of the net before falling onto Robredo's side of the court for the winner.

But there was disappointment for French Open winner Stan Wawrinka who was unable to carry on due to apparent back problems, with the Swiss quitting to hand a 6-7 (8/10), 6-4, 4-0 victory to Australian Nick Kyrgios.

Wawrinka, who did not play after Wimbledon due to a shoulder injury, called for the trainer as he trailed two breaks in the third set.

After speaking with the trainer and his coach Magnus Norman, the 30-year-old third seed decided to give up the match.

Murray set up a meeting with Gilles Muller -- whom he has defeated twice this season -- as he finished his second round contest with 24 winners and 30 unforced errors and breaking four times.

The pair resumed play Wednesday after standing 4-4 in the opening set when the rain stopped play on Tuesday night.

"It was a very tough match, there were a lot of nerves near the end of the first set," said Murray. "I won two close games to take it.

"Conditions today were a lot different, there was a lot of wind. It was difficult to attack and play aggressively. I had to chase down a lot of balls and got lucky a few times as well”

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.

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 rubberized 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 in Canada for the first time since winning his third title here in 2013. The world number nine improved to 40-12 on the season.

"I go day by day. Today is a victory that I am happy with," said Nadal.