Serena, Sharapova reach Miami quarters

Five-time champion Serena Williams was a come-from-behind fourth-round winner Monday at the $4.195 million Sony Open tennis event.

The world No. 1 superstar clawed back in order to beat game 13th-seeded Slovak Dominika Cibulkova 2-6, 6-4, 6-2 on the hardcourts at Crandon Park. Williams trailed 2-6, 1-4 before mounting one of her trademark comebacks in 1 hour, 57 minutes, as the American great swatted 14 aces, including a match-ending one, en route to victory.

Williams swept the final five games of the second set and went ahead to stay by breaking serve at love for a 2-1 lead in the final stanza.

The reigning Wimbledon and U.S. Open champion has appeared in seven Sony Open finals, including three straight titles from 2002-04 and back-to-back championships in 2007 and 2008.

Williams' quarterfinal opponent will be dangerous Australian Open runner-up Li Na of China. The fifth-seeded Li advanced with a 7-6 (8-6), 6-2 victory over surprise Spaniard Garbine Muguruza on Day 7.

Maria Sharapova, fresh off her win at Indian Wells, highlighted the bottom half of the draw with a quick 6-2, 6-2 disposal of 21st-seeded Klara Zakopalova.

Next up for Sharapova is a meeting with eighth-seeded Italian Sara Errani, a 1-6, 6-4, 6-2 winner over 12th-seeded Ana Ivanovic.

Fourth-seeded and defending champion Agnieszka Radwanska fought back for a quarterfinal berth by besting 16th-seeded American and Aussie Open semifinalist Sloane Stephens, 4-6, 6-2, 6-0.

Radwanska downed four-time Miami runner-up Sharapova in the finals last year. She next faces another comeback winner in 30th-seeded Belgian Kirsten Flipkens, who overcame Croat Ajla Tomljanovic 6-7 (6-8), 6-4, 6-3 to reach the round of eight.

The other quarterfinal will pit 15th-seeded Italian Roberta Vinci and former world No. 1 Jelena Jankovic. Vinci took down 32nd-seeded Alize Cornet of France, 2-6, 6-4, 6-4, while the 22nd-ranked Jankovic ousted 28th-seeded Sorana Cirstea by a 6-0, 6-4 margin.

Jankovic was the Miami runner-up in 2008.