NEW YORK // Vera Zvonareva, the Russian second seed, reached the US Open last 16 Friday with a 6-4, 7-5 win over Spain's Anabel Medina Garrigues, the 30th seed.
Medina Garrigues has never been past the third round at the US Open.
Zvonareva, the runner-up to Kim Clijsters in 2010, will face either the German 22nd seed Sabine Lisicki or Irina Falconi of the United States for a place in the quarter-finals.
She will need to get sharper - Zvonareva won despite making 35 unforced errors.
On the men's side, Juan Martin del Potro, the 18th seed from Argentina, defeated his countryman, Diego Junqueira, 6-2, 6-1, 7-5. The 30-year-old Junqueira is ranked 104th and was playing in his first US Open. He has never been past the second round at a grand slam event.
Del Potro, who won the tournament in 2009, was unable to defend his title last year because of wrist surgery.
Wozniacki, who has won 18 career titles including six this season, but is still seeking her maiden grand slam victory, had the ear of the 29 year old, 13-time major winner, but might have wasted the opportunity.
The 21-year-old Dane, who is dating the Masters golf champion, Rory McIlroy of Northern Ireland, asked the three-time US Open champion about her love life.
"I hope she didn't listen," Williams said to reporters after her second-round win on Thursday. "I told her never look through the guy's phone. That is the worst thing you can do. I told her most relationships end. It wasn't very good advice."
Wozniacki, who walloped unseeded Arantxa Rus of the Netherlands 6-2, 6-0 to advance to the third round, said it was all in good fun.
"Well, we were all in the locker room," Wozniacki said. "I was going to get some treatment. She [Serena] was sitting there, with Venus, and talking.
"And then, I don't know, it just came out that we were talking a bit and we had a laugh. We were just kidding around a little bit."
McIlroy, apparently, can breathe easy.
"Yeah, I think I should not listen to her or Venus," the Dane said. "She [Venus] was not better."
In other news, Rafael Nadal will not have to worry about any hairy situations cropping up for him while at the US Open, because his barber has his back.
Nadal's New York hairdresser claims he has been offered US$250 (Dh918.27) to sell the Spanish star's shorn locks, but Julien Farel, who runs the salon on the city's Madison Avenue, and has cut Nadal's hair at every US Open for the last five years, will not indulge fans who want a piece of the defending champion.
The stylist told the New York Post daily newspaper that he has "too much respect" for Nadal, "even though I could make a lot".