American Andy Roddick survived the second longest match in Australian Open history. But only just.

Five hours after he stepped onto the court against Morocco's Younes El Aynaoui, he walked off a 4-6 7-6 (7-5) 4-6 6-4 21-19 winner.

The bad news is that he has to play another two matches if he is to win the tournament.

Roddick, 20, is into his first grand slam semi-final, but if the quarter-final had gone much further he might have been on his way to hospital.

In a match whose 83 games made it the longest here in the Open era in terms of games played, Roddick outlasted an opponent 11 years his senior, but one who ran with him to the end.

"I don't think I'll be doing that when I'm 31," Roddick said.

Roddick said he thought El Aynaoui was spent at 13-all in the fifth.

But the Moroccan dragged another hour's play out of a body that seemed likely to fail him at any moment.

The end of the marathon came almost two hours after Roddick saved a match point at 30-40 and 4-5 in the fifth set and an hour after he served for the match at 11-10.

For Roddick, the final set turned into a battle against his notoriously shaky temperament as much as against his opponent.

Brought to you by AAP © 2024 AAP