MELBOURNE, Australia — After taking a tumble on the next-to-last point of the match, Serena Williams got up and whipped a backhand winner down the line to finish off her second-round match at the Australian Open and her 500th career win.
With the 6-0, 6-4 victory over Barbora Zahlavova Strycova on Thursday, Williams extended her winning streak to 16 matches at Melbourne Park, where she won back-to-back titles in 2009 and '10 but couldn't play last year because of injury.
Her participation had been in doubt again after she badly sprained her ankle two weeks ago at a warm-up tournament, which is why the Rod Laver Arena went silent when Williams fell onto the court in the penultimate rally and sat, watching, as Strycova's shot floated out.
"It's fine. I just have wobbly ankles," she said in a TV interview after the match. "I wasn't meant to be a ballerina or anything."
It was the 500th win on tour, something she'd wanted to achieve since her older sister, Venus, passed the milestone.
"I knew I had to get there too, because I do everything she does," she said. Venus Williams, a seven-time Grand Slam winner with a career record of 598-147 as a pro, is skipping the Australian Open to recover from illness.
Serena Williams now has 500 wins and 104 losses in her career.
Maria Sharapova, one of the other two former champions in the draw, reached the third round after just two hours on court. The 2008 champion had a 6-0, 6-1 second-round win over U.S. qualifier Jamie Hampton in 64 minutes, two days after beating Argentina's Gisela Dulko by the same margin.
Sharapova did not play in any warm-up events and spent nearly two weeks in Melbourne ahead of the season's first major while she rested an injured left ankle.
"It was more about getting my feet going ... worrying about myself," Sharapova said. "Yeah, started my preparations in the off-season a little late, took a bit of extra time in practice instead of rushing into a tournament."
Two seeded players were ousted, with Sara Errani beating No. 29 Nadia Petrova 6-2, 6-2 and No. 25 Kaia Kanepi's strong start to the season coming to an end in a 6-2, 7-5 loss to Ekaterina Makarova of Russia.
Defending champion Kim Clijsters and top-ranked Caroline Wozniacki are into the third round on the other half of the draw.
On the men's side, No. 2 Rafael Nadal advanced without much trouble from his injured right knee or from German veteran Tommy Haas in a 6-4, 6-3, 6-4 win. Four-time champion Roger Federer didn't even need to pick up a racket because Andreas Beck withdrew from their second-round match.
The top-ranked American man bowed out when No. 8 Mardy Fish lost to Alejandro Falla of Colombia 7-6 (4), 6-3, 7-6 (6). But No. 16 John Isner survived a five-setter to beat former Wimbledon finalist David Nalbandian, who was enraged by an umpire who didn't allow him to challenge a disputed line call because he took too long to ask for a review.
No. 7 Tomas Berdych, 2009 U.S. Open champion Juan Martin del Potro and No. 18 Feliciano Lopez all advanced.
Andy Roddick was scheduled to play the last match Thursday against Lleyton Hewitt in a battle between two former No. 1-ranked players.