Nick Kyrgios opens Rogers Cup campaign with victory

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 centre 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."

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).