Stan Wawrinka is anticipating another tough encounter against Milos Raonic at the Australian Open, despite his unbeaten record against the big-serving Canadian.

Swiss fourth seed Wawrinka continued his quest for a second Australian Open title with a 6-2, 6-3, 7-6 (7-3) win over Lukas Rosol on Saturday.

Wawrinka - the 2014 champion - chalked up 18 aces in the routine triumph as he stayed unbeaten in 2016 courtesy of his 400th career ATP victory.

The French Open holder now turns his attention to 13th seed Raonic, who is winless in all four previous matches against the Swiss. However, Wawrinka is not taking his superior head-to-head record for granted with a quarter-final berth on the line.

"He's tough player. I have never lost, but always been some tough matches," Wawrinka said post-match.

"He's been playing really good since the beginning of the year, winning the first title in Brisbane against Roger [Federer] in the final. He's trying to improve. He's trying to go there. He's trying to win a big title. It will be a difficult match for sure. He's serving big. I played him in Abu Dhabi [in an] exhibition. I lost first match of the year. He changed few things in his game.

"I still think it depends a lot on my game, of what I'm going to do, of where I'm going to be on the court, the way I'm going to serve. In general, I always find some solution to break his serve, even though it is really tough. We'll see. Hopefully I can be ready and be strong enough to take that one. But for sure it's going to be a really difficult match."