Milos Raonic beat Tommy Robredo in unusual fashion at the Australian Open on Thursday when he secured victory with the only service break of the match -- after nearly three hours of play, and in the very last game.

The big-serving Canadian finally broke Robredo's serve at the 12th attempt and in the 36th game to win it 7-6 (8/6), 7-6 (7/5), 7-5 and reach the third round after two hours and 55 minutes.

Raonic's reward is a round of 32 meeting with Serbian 21st seed Viktor Troicki, who won last week's Sydney International.

"I don't think I played as clean as I would have liked, but at the end of the day, the most important thing is I got the win," Raonic said.

"I'm impressed by how hard he fought. He didn't surprise me by any means. It's what you expect.

"I think he's probably one of the guys that has probably the most saved match points in matches."

The Canadian 13th seed, who reached the quarter-finals of last year's Australian Open where he lost to eventual winner Novak Djokovic, hit 24 aces among his total of 75 winners.

Raonic said he was looking for a more efficient performance against the in-form Troicki in his next match.

"It's going to be difficult. He won last week, so he's feeling well," he said. "He battled through also a difficult match on the first day, saving match points and then he had a good win today.

"I think if I can put my game together a little bit cleaner and more efficient than I did today, be a little bit more proficient at the net, dictate a bit better, I'll be able to give myself some opportunities."

The experienced Spaniard Robredo resisted stoically throughout and saved 11 of 12 break point opportunities until he finally crumbled at the crucial moment in the third set.