CHARLESTON, S.C. — Second-seeded Venus Williams struggled to advance at the Family Circle Cup on Wednesday, beating Sania Mirza of India 6-1, 3-6, 6-2.

It took the fifth-ranked Williams almost 2› hours to defeat the 100th-ranked Mirza on the green clay of stadium court at the tennis center on Daniel Island. Williams, who won the Family Circle five years ago, is now 3-0 against Mirza.

"When she's playing against me, she's got to go for it and I think there's also a sense of nothing to lose," Williams said. "When you look at the numbers and the rankings and statistics, you know, I'm supposed to win this match, so I think that gives her an opportunity to swing freely."

It appeared Williams had the match well in hand, winning the first set 6-1, although it took 46 minutes to do so. She led 3-1 in the second before Mirza rattled off five straight games, including breaking Williams at love to take a 5-3 lead and holding serve in the final game, which went to deuce eight times.

Williams recovered to easily win the third set.

"These kind of matches are great to pull out," she said. "I've been in these situations before, so I rely on that."

While Williams struggled, it was a big day for fellow-American Melanie Oudin, who advanced to the third round with a 7-5, 6-0 victory over No. 29 Aleksandra Wozniak, seeded ninth.

"I was really happy with the way I played and how I kept it up, especially through playing a set and not letting her come back at all," said Oudin, ranked No. 176.

The 17-year-old from Marietta, Ga., called it one of the biggest victories of her career.

"This is definitely one of the top two biggest highlights I have had," she said, the other coming when she beat Sybille Bammer, who was ranked No. 27 at the time.

Oudin will face 13th-ranked Marion Bartoli of France in the next round of the $1 million Family Circle Cup.

In other matches Wednesday, 11th-seed Alona Bondarenko was ousted by Viktoriya Kutuzova 6-4, 7-5, and 12th-seeded Bethany Mattek-Sands was defeated by Anastasia Rodionova 6-2, 6-4. Sabine Lisicki, seeded 16th, advanced with a 6-4, 6-3 win over Lenka Wienerova and now faces Williams.

Fifth-seeded Caroline Wozniacki faced Alla Kudryavtseva of Russia in an evening match.