French third seed Mauresmo was only on court for 30 minutes after Michaella Krajicek retired hurt. Mauresmo raced to a 4-0 lead and took the first set 6-2 before 17year-old Krajicek called for the trainer and soon after conceded defeat.

Russian 12th seed Myskina overcame Sweden's Sofia Arvidsson in a scrappy affair, the pair committing more than 60 unforced errors between them in only an hour of tennis. Myskina claimed the first set before racing to a 5-0 love lead in the second on the way to eventually closing out the match 6-3, 6-1.

Australia's great hope Stosur continued her solid form to win through to her firstever fourth round singles appearance at a Grand Slam . . . defeating Austrian Sybille Bammer 7-5, 4-6, 6-3. Though she was not at her best in a match which saw the pair trade plenty of breaks of serve, Stosur will now meet former world number one Hingis in a much-anticipated match after the Swiss Miss continued her stellar comeback to the game. Hingis beat Czech Iveta Benesova 6-4, 61, and has now dropped only 10 games in the tournament.

Clijsters brushed aside her opponent . . . Italian Roberta Vinci . . . and her injury worries to win 6-1, 6-2. The Belgian number two seed is now through to the round of 16 and will be hoping to repeat her third round efforts over the next week.

Former Australian Open semi-finalist Schnyder and Aiko Nakamura both struggled to hold serve in their match with 10 breaks in just 17 games. Nakamura won fewer than a quarter of the points on her second serve, helping the Swiss seventh seed progress to the fourth round 6-2, 6-3. Sixteen-yearold Nicole Vaidisova and Italian 20th seed Flavia Pennetta also found serving difficult, but the Czech 16th seed showed why she is touted as a player for the future with a 6-4, 6-2 win.

There was also no stopping the big gun in the men's draw, Roger Federer, who is on track for a second Australian Open title in three years.

He comfortably defeated Belorussian Max Mirnyi to reach the fourth round at Melbourne Park. The world number one cruised to a 6-3, 6-4, 6-3 win over Mirnyi to set up a clash against German Tommy Haas . . . who beat him at last week's exhibition Kooyong Classic in Melbourne.

Federer got off to a brilliant start with an early break giving him the momentum as he went on to easily claim the first set, but the number one seed found it more difficult in the second set. Pressured a couple of times on serve, the 30th-seeded Mirnyi saved break points with aces but, after six break-point attempts, Federer finally broke through in the seventh game and had no trouble wrapping up a two-set lead.

The Swiss ace went up a gear in the third set, breaking Mirnyi's serve in the opening game, and any hope of a Mirnyi fightback was gone when a few trick shots brought the crowd to their feet.

Meanwhile, Haas's brilliant serving helped him recover from a set down to beat home hope Peter Luczak 4-6, 6-3, 64, 6-4. Sebastien Grosjean, Paul-Henri Mathieu Dominik Hrbaty and Juan Ignacio Chela also made it through.