The 6-0, 6-1 defeat was the worst of Kim Clijsters's career and as one-sided as the score indicated. The 6-0, 6-1 defeat was the worst of Kim Clijsters's career and as one-sided as the score indicated. (Clive Brunskill/Getty Images)

The much-anticipated potential quarter-final between the back-from-retirement Belgians dissolved in 52 minutes on Friday at the Australian Open.

That's the time it took for Kim Clijsters to lose, in embarrassing fashion, her third-round match at the season's first Grand Slam tournament.

The 6-0, 6-1 defeat to Nadia Petrova was the worst of Clijsters's career and as one-sided as the score indicated. Clijsters lost the first set in just 18 minutes and won only five points in her first seven games.

Justine Henin, another Belgian who was inspired to return to the tour following a 20-month absence after Clijsters won last year's U.S. Open, had earlier held up her end of the bargain, with some difficulty, in beating Alisa Kleybanova 3-6, 6-5, 6-2. The two Belgians had been on track to meet in the final eight at Melbourne Park.

"I just didn't give her a chance to get into the match," Petrova said. "I like this kind of Grand Slam feeling."

'I was completely off'

Clijsters hadn't been on the receiving end of such a lopsided scoreline since losing the French Open final to Henin 6-0, 6-4 in 2003.

"I was completely off. I think tennis-wise, I didn't feel the ball at all," Clijsters said. "On the other hand, she was good, but I made all the mistakes and she really didn't have to do much."

Defending champion Rafael Nadal advanced to the fourth round Friday along with Andy Murray, U.S. Open champion Juan Martin del Potro, Andy Roddick and Fernando Gonzalez.

Nadal, who beat Roger Federer in last year's final, beat Philipp Kohlschreiber of Germany 6-4, 6-2, 2-6, 7-5 in a night match. The Spaniard broke Kohlschreiber's serve in the 11th game of the fourth set, then held serve to take the match with a forehand winner.

In the fourth round, Nadal will play Ivo Karlovic, who beat Ivan Ljubicic 6-3, 3-6, 6-3, 7-6 (9-7).

The fifth-seeded Murray, bidding to win his first Grand Slam singles title, beat Florent Serra of France 7-5, 6-1, 6-4 and is one victory away from a potential quarter-final with Nadal.

First, Murray will have to beat American John Isner, winner of the Auckland tournament last week for his first ATP title. The six-foot-nine Isner continued his strong form by beating 12th-seeded Gael Monfils of France 6-1, 4-6, 7-6 (7-4), 7-6 (7-5).

No. 4 Del Potro beat Florian Mayer of Germany 6-3, 0-6, 6-4, 7-5 and No. 7 Roddick advanced 6-7 (4-7), 6-4, 6-4, 7-6 (7-3) over Feliciano Lopez of Spain.

Next up for del Potro is Marin Cilic, who beat Stanislas Wawrinka 4-6, 6-4, 6-3, 6-3.

Gonzalez, the 2007 finalist here, beat Evgeny Korolev of Kazakhstan 6-7 (5-7), 6-3, 1-6, 6-3, 6-4. Roddick and Gonzalez will play each other Sunday in the fourth round, with the American holding an 8-3 edge in career meetings, including a straight-sets win the last time they met in the round of 16 at the 2008 U.S. Open.

Henin's match Friday was her eighth since she returned from retirement, just long enough to expect better of herself as a seven-time Grand Slam singles champion.

Henin will play Yanina Wickmayer in the fourth round.

Sarafina advances

Wickmayer, who is ranked No. 16 but unseeded because she was under a suspension — since overturned — for breaching the World Anti-Doping Agency's "whereabouts rule" when direct entries closed for the Australian Open, advanced 6-1, 6-7 (4-7), 6-3 over Sara Errani.

Second-seeded Dinara Safina, the 2009 finalist, advanced with a 6-1, 6-2 victory over Britain's Elena Baltacha.

Safina will have a more difficult assignment next round against fellow Russian Maria Kirilenko, who beat Italian Roberta Vinci 7-5, 7-6 (7-4). Kirilenko also beat 2008 champion Maria Sharapova in the opening round.

Former No. 1-ranked Jelena Jankovic was upset 6-2, 6-3 by No. 31 Alona Bondarenko.