Venus Williams pulls out of Australian Open with injury

The seven-times grand slam champion pulled up with what appeared to be a groin strain after just seven points.

A trainer attends to Venus Williams before she decide to retire against Andrea Petkovic of Germany.

MELBOURNE // The fourth seed Venus Williams retired from her Australian Open third round match against Germany's Andrea Petkovic with injury on Friday after lasting just seven points.

The seven-times grand slam champion pulled up with what appeared to be a groin strain after lunging for a return with the German leading by a game and 30-0 in Melbourne.

Petkovic moves on to face former champion Maria Sharapova in the fourth round.

Williams strained a muscle in the same area during her second round victory over Czech Sandra Zahlavova on Wednesday.

Her retirement leaves a grand slam without an American woman in the last 16 for only the fourth time, the last time coming at the French Open in 2008.

"I just obviously couldn't play," she said. "I mean, just couldn't move. Just too painful ... A lot times when you play you get this adrenaline that blocks pain. But I just didn't get enough of that today."

Henin, like Williams a seven-times grand slam champion, was still clearly hampered by the elbow injury that wrecked her 2010 campaign as she bowed out 6-4, 7-6 to Svetlana Kuznetsova.

Henin, who made a fairytale run to the final last year on her return from retirement, made her earliest exit from Melbourne Park in 11 visits.

The 2004 champion racked up 41 unforced errors and even her Russian opponent's late nerves could not save her. "It's disappointing to lose like this," said Henin. "She was just better than me, especially in the important moments."

Kuznetsova's reward was a tie against her friend and French Open champion Francesca Schiavone after the Italian beat Romanian Monica Niculescu 6-0, 7-6. "We have a great friendship," the Russian said of Schiavone. "But we are both athletes. Out on court we're animals and kind of fighters against each other."

Sharapova, lone champion in the fray

Henin's departure leaves Maria Sharapova as the only former champion in the women's draw.

The Russian, seeded 14th, made hard work of beating German Julia Goerges 4-6, 6-4, 6-4 but said she was delighted with her fitness after a 2 1/2-hour win set up a meeting with Petkovic. Djokovic, who like Sharapova is trying to emulate his 2008 triumph here, saved some energy when Troicki retired with a muscle strain after losing the first set and hopes that will stand him in good stead for the challenges of the second week.

"They are physically very fit and mentally very strong," he said of Rafa Nadal and Federer who will stand in his way. "It seems like they're raising their level of performance in the second week of the grand slams."

Gael Monfils paid the price for playing nine sets in his first two rounds as the French 12th seed went out 7-6, 6-2, 6-3 to Swiss Stanislas Wawrinka.

Spaniard Fernando Verdasco, however, brushed off his five-set second round thriller to beat Japan's Kei Nishikori 6-2, 6-4, 6-3 and set up a fourth round meeting with Czech sixth seed Thomas Berdych, who cruised past Richard Gasquet 6-2, 7-6, 6-2.

Women's world No1 Caroline Wozniacki moved comfortably into the fourth round with a 6-4, 6-3 win over Dominika Cibulkova before having a bit of fun with the media.

The 20-year-old Dane took charge of her post-match press conference, giving the answers to stock questions before they were asked.

She then held court on topics as diverse as Liverpool soccer club and global warming but inevitably the questions over her legitimacy as No 1 without a grand slam title.

"I feel like I deserve to be there," she repeated. "I've done so well last year, and hopefully I can continue my roll this year. I know that you guys have to write about something, and that's a pretty good question to ask."

Roddick powers past Haase with 32 aces

Andy Roddick overcame a slow start before powering home with 32 aces to beat Robin Haase 2-6, 7-6 (2), 6-2, 6-2 and move into the fourth round of the Australian Open.

The eighth-seeded Roddick is seeking his second Grand Slam title nearly seven years after his first – the 2003 US Open.

Haase received treatment on his right ankle early in Friday's first set, getting it heavily taped after appearing to stumble on a shot. The trainer was back out at the end of the set for Haase, who broke Roddick's serve twice.

The Dutchman, despite the injury, made the shot of the tournament so far, chasing down a Roddick lob and hitting a flick backhand over the net while facing the back of the court. Haase won the point two shots later.