(Reuters) - Temperamental Australian Nick Kyrgios looked fresh and focused as he blazed to a 6-1 6-2 first round win over Viktor Troicki at the Rogers Cup in Montreal on Monday but warned he was rolling the dice with a hip injury that could flare up at any time.
The wobbly hip that hit Kyrgios's grasscourt season, with first-round retirements at London's Queen's Club and Wimbledon, have followed him into the North American hardcourt season.
But the 16th seed showed no signs of distress in dispatching Troicki after 51 minutes on a sun-kissed center court.
"I'm feeling it all the time," said Kyrgios. "It's not something that is just going to heal. I can compete so that's the most I can do at the moment."
With his mother watching from the stands, the hot-headed Australian kept his cool against an overmatched opponent who has been struggling with his own injury issues.
Tennis fans never quite know what to expect when Kyrgios steps onto the court.
Will it be the immensely skilled athlete hailed as a future grand slam winner or the pouty, petulant player going through the motions?
On opening day, at least, the fans saw a motivated Kyrgios playing near his best and treating the crowd to a display of power and finesse.
The only lapse in an otherwise dominant effort was Kyrgios's inability to deliver the knockout punch with the 22-year-old needing seven match points to finish off the 45th ranked Serb.
"I just wanted to come out here and try and get the win," said Kyrgios. "I've been struggling the last couple of months.
"He's been struggling as well with injuries so all the best to him but I'm just happy to get out here and get a win."
In later games, Juan Martin del Potro withstood 24 aces from John Isner to knock off the big-serving American 7-5 7-5.
Del Potro, a 2009 finalist at Montreal, broke Isner’s service while tied at 5-5 in both sets to advance.
Isner had been red hot after capturing back-to-back tournaments in July.
“I got lucky to win tonight,” Del Potro said. “Hopefully I can get another draw in the next tournament because nobody wants to play against John in the first round.”
Roberto Bautista Agut rolled past Tim Smyczek 7-6(4) 6-1,while American Jared Donaldson, 66th in the world, provided the first upset of the tournament by knocking out French 13th seed Lucas Pouille, twice a title winner this season, 7-6(5) 7-6(8).
(Reporting by Steve Keating in Toronto; editing by Ken Ferris/Peter Rutherford)