LONDON, England - It may have taken her a few sets to really find her rhythm, but Serena Williams finished strong in her second match at Wimbledon on Thursday, playing a near-flawless third set to beat Simona Halep, 36 62 61.

Williams, ranked No.25 but seeded No.7, was outsteadied in the first set by the 19-year-old Halep, a former No.1 in the juniors who has had some strong results on clay so far in the seniors. But once the first set was set aside Williams really hit her stride, hitting 24 winners to 10 unforced errors in the next two sets to prevail, not even allowing Halep a single winner in the 28-minute third set.

Things got a little dicey at 5-0 and triple match point, as Williams' game went slightly off and she lost seven straight points; but she quickly ended the streak, winning four points in a row from 0-30, finishing the match off with a big first serve - she won 100% of first serve points in the third set as well.

"Usually players that height don't serve as well - she has so much power on her serve, that's actually really awesome," Williams said of the 5'6" Halep. "I feel like I started slowly today, but I was actually really, really trying to start out fast. That obviously didn't happen. I got a little tight out there and I just need to relax.

"I'm just playing my way into match condition. That's all I can do."

Williams has now reached the third round or better at her last 43 Grand Slams. In those 43, though, the only time she was pushed to three sets in both of her first two matches, she lost in the third round (she beat Angela Haynes and Mara Santangelo in three sets here in 2005, then lost to Jill Craybas).

Next for Williams is No.26 seed Maria Kirilenko, who beat former Wimbledon quarterfinalist Tamarine Tanasugarn, 75 75. Tanasugarn was a qualifier.

"She moves well and hits hard. Boy, she runs well," Williams said of Kirilenko. She does everything well. And she's always looking to improve. It will be tough."

Also on the schedule early on were second round matches that were postponed from Wednesday, with No.6 seed Francesca Schiavone, No.12 seed Svetlana Kuznetsova, No.19 seed Yanina Wickmayer and unseeded players Nadia Petrova, Tamira Paszek and Kateryna Bondarenko all moving through. Petrova, a former Top 3 player, pulled off one of the biggest upsets of the week so far, beating No.14 seed Anastasia Pavlyuchenkova, 63 63.

Schiavone, who celebrated her 31st birthday on Thursday, was asked how she felt on her special day after a 75 63 win over Barbora Zahlavova Strycova.

"I feel a little bit older," the Italian joked.