KEY BISCAYNE, Fla. — Venus Williams has won her opening match at the Sony Ericsson Open by beating Sorana Cirstea 6-4, 6-3.

Both sets followed similar patterns Thursday night, with Williams losing serve early and finishing strong. She swept the final four games of the first set and the final three games of the match.

Williams won despite an inconsistent serve. She had five aces but also five double faults.

Seeded third, Williams is bidding for her fourth Key Biscayne title, but her first since 2001. Her third-round opponent will be unseeded Roberta Vinci, who beat No. 30 Anabel Medina Garrigues 6-4, 7-6 (5).

Williams has won 11 matches in a row. She's playing for the first time since February, when she earned titles at Dubai and Acapulco.