Australian teenager Lleyton Hewitt played half way through the night to defeat American Paul Goldstein at the Australian Open.

Hewitt, aged 18, stretched his unbeaten winning streak this year to 11 matches with a marathon four-set victory.

It was 2am when Hewitt finally finished his match which had been delayed due to rain.

Despite the late hour, a large crowd had remained to see the tournament's fourth favourite's opening match.

Hewitt, ranked No 1 in the new ATP Champions Race after winning the Australian men's hardcourt and Sydney international titles, won the first set 6-2.

But Goldstein stunned the majority of the crowd by rallying to take a second-set tie-break almost on the stroke of midnight.

With both players visibly tiring, Hewitt won a 68-minute third set on another tie-break before clinching the match by winning the thrilling fourth set 6-4 only nine minutes before a 2am deadline set by the organisers.

Hewitt faces a similarly tough task in the second round when he faces former world number two Alex Corretja. But after beating the Spaniard in Sydney last week the teenager will start a clear favourite.

'No easy points'

"There were no easy points. It was tough tennis out there and it really has taken a lot out of me," an exhausted Hewitt said.

"I'm match hardened at the moment, I just hope I have the stamina to go the two weeks."

By the time Hewitt took to the court, three men's seeds had already crashed out of the tournament amid complaints about the playing surface.

Three-time Wimbledon runner-up Goran Ivanisevic knocked out 13th seed Cedric Pioline 9-7 in the fifth set.

Fifth seeded Brazilian Gustavo Kuerten was beaten by Spaniard Albert Portas, also in five sets.

And there was defeat for Albert Costa, the Spanish 15th seed, in four sets by Belgian Christophe Rochus.

Yefgeny Kafelnikov began his title defences with a win.

The Russian was a set down to German Jens Knippschild and needed treatment for a groin injury before coming through 6-7 (7-4) 6-4 6-1 6-2.

He was one of the top players to complain about the playing surface.

"It's ridiculously fast compared to last year," he said.

"The ball is travelling through the air a lot quicker, so it definitely favours big serve players like Sampras, Philippoussis and Krajicek."