World number one Roger Federer survived an inconsistent form to beat Florent Serra 7-6 (7-2), 7-6 (7-3) on Monday in the third round of the WTA and ATP tournament in Miami, the United States.

Federer lost serve three times, each time when he led. He committed 35 unforced errors to 32 for Serra.

But Federer won eight consecutive service points in the tiebreakers and closed out the victory with a service winner.

Switzerland's Roger Federer returns a shot to France's Florent Serra during their match at the Sony Ericsson Open tennis tournament in Key Biscayne, Florida, March 29, 2010

The top-seeded woman, Svetlana Kuznetsova, was hampered by a right shoulder injury and lost to Marion Bartoli 6-3, 6-0 in the fourth round.

Kuznetsova, the 2006 champion, required treatment from a trainer three times during the match and won only eight points in the second set.

Mardy Fish reached the fourth round with his second consecutive win over a seeded opponent, beating No. 29 Feliciano Lopez 7-5, 6-3. Fish upset defending champion Andy Murray in the second round.

【体坛英语资讯：Federer beats Serra to reach fourth round in Miami】相关文章：

★ 体坛英语资讯：Peng upsets Mauresmo to reach semis at China Open

★ 体坛英语资讯：Another big shots out, coach says worlds lose meaning

★ 体坛英语资讯：Torres and Gerrard hand Liverpool win over Shanghai

★ 体坛资讯：Henman tops Moya to advance at Wimbledon

★ 体坛英语资讯：NBAs spectacular China games just the tip-off

★ 体坛英语资讯：Celtics and Lakers square off in leagues top rivalry

★ 体坛英语资讯：Coach cares for Liu like a son

★ 体坛英语资讯：Pairs skaters challenged by system

★ 体坛英语资讯：Liu begins training in isolation

★ 体坛英语资讯：Rocket explosion