MELBOURNE (AFP) - Andy Roddick served his way into the third round of the Australian Open, overcoming German Michael Berrer in straight sets on Wednesday.

The American sixth seed met resistance but rounded off a 6-2, 6-2, 6-4 win in one hour 58 minutes.

Roddick, a three semi-finalist here, will next play another German Philipp Kohlschreiber and is on course for a quarter-final with second seed Rafael Nadal.

Roddick needed five match points to finally snuff out Berrer's stubborn resistance.

"He was trying to hit the ball hard around the court and it was a good workout ahead of my next match," Roddick said.

Roddick broke the German twice to take the opening set in 29 minutes.

Berrer surprised the sixth seed with his quick reflexes at the net and powerful backhand, but 15 unforced errors cost him.

Roddick's serve was on song, humming along at 68 percent, and he had Berrer under pressure.

Berrer had three break points against him in the fifth game of the second set and dropped serve with a double-fault on the third one.

The German left-hander came increasingly under pressure during the second set and lost his service in his next game to leave Roddick to comfortably serve it out for a two sets to love lead.

Roddick worked his serve into top gear and was crunching home aces clocked around 215 kph.

But Berrer kept at it and was rewarded with a service break when on his second break point in the second game of the third set Roddick mishit a volley and slammed his racquet into the court in disgust.

Roddick hit back breaking Berrer's serve and levelling game scores in the sixth.

Berrer came under renewed pressure and on his fourth break point netted an easy smash to put Roddick on the way to victory.

Roddick, in the bottom half of the men's draw and away from 12-time Grand Slam champion Roger Federer, is looking to do better than his best finish of three semi-final appearances here.

Coached by American great Jimmy Connors, Roddick came into the year's opening Grand Slam tournament having won the lead-up Kooyong Classic exhibition for the third straight time, beating Cypriot Marcos Baghdatis in last Saturday's final.

America's top player finished in the top-10 for the sixth straight season and led the United States to its first Davis Cup title since 1995 against Russia last month.