Andy Roddick, the US No 8 seed, is through to the third-round of the Australian Open for the ninth consecutive year after firing his 17th ace of the match to finish off a 7-6 (7), 6-2, 6-3 win over Igor Kunitsyn of Russia.
The big hitting former world No 1 says he is finding his range at Melbourne Park.
"I think when you're confident, the court just makes sense; decisions come easier to you," Roddick said. "A lot of it comes naturally. There's not a whole lot of thought process. You're not forcing a lot. The ball kind of, I guess, reacts the way you want it to.
"So I feel comfortable out there right now."
Roddick's friend and US Davis Cup teammate Mardy Fish made a second-round exit, the No. 16 seed losing 1-6, 6-3, 6-3, 6-3 to Tommy Robredo.
Wimbledon finalist Tomas Berdych needed four match points, struggling to finish it off with his serve in the last game, to beat Philipp Kohlschreiber 4-6, 6-2, 6-3, 6-4.
Fernando Verdasco rallied from two sets down to beat Serbia's Janko Tipsarevic 2-6, 4-6, 6-4, 7-6 (0), 6-0, conceding just one point on his serve in the last set.
Verdasco has a history of five-set matches here – his five hour, semi-final defeat to Rafael Nadal two years ago was the longest match ever at the Australian Open.
The No 17 seed Ivan Ljubicic and the No 28 seed Richard Gasquet also advanced, while Japan's Kei Nishikori beat Germany's Florian Mayer 6-4, 6-3, 0-6, 6-3.