KEY BISCAYNE, Fla. — Serena Williams looked right at home, and not just because her purple dress matched the color of the court.

KEY BISCAYNE, Fla. — Serena Williams looked right at home, and not just because her purple dress matched the color of the court.

Playing in her backyard tournament for the first time since 2009, the five-time champion beat wild card Zhang Shuai 6-2, 6-3 on Thursday at the Sony Ericsson Open.

The victory marked Williams' return to tournament tennis after a two-month absence. It was her first match at Key Biscayne since she lost to Victoria Azarenka in the final three years ago.

American Ryan Harrison, a wild card entry, rallied past Polito Starace 6-7 (6), 6-4, 6-4 and will next face two-time champion Roger Federer.

No. 2-seeded Maria Sharapova overcame 12 double-faults and erased 10 break points to rally past Shahar Peer 4-6, 6-3, 6-3. No. 4 Caroline Wozniacki beat Barbora Zahlavova Strycova 6-4, 6-0.

Two-time champion Kim Clijsters won for the second day in a row, beating No. 14-seeded Julia Goerges 6-2, 7-5. No. 13 Jelena Jankovic lost her opening match to Mona Barthel 6-0, 6-3.