Miami defending champion advances to quarterfinals

Defending champion Agnieszka Radwanska advanced to the quarterfinals of the Sony Open today when she defeated Sloane Stephens in the fourth round. Once again, Radwanska had to go three sets, but she won the third set 6-0. Also advancing was Serena Williams, who defeated Dominika Cibulkova 2-6, 6-4, 6-2. Sorana Cirstea, who upset Angelique Kerber in straight sets in the fourth round, fell in straight sets today to Jelena Jankovic.

Here is the quarterfinal draw:

Serena Williams (1) vs. Li Na (5)
Agnieszka Radwanska (4) vs. Kirsten Flipkens (30)
Sara Errani (8) vs. Maria Sharapova (3)
Jelena Jankjovic (22) vs. Roberta Vinci (15)

Top double seeds Errani and Vinci advanced to the quarterfinals with a win over Timea Babos and Mandy Minella.

The quarterfinal to watch (and one I won't get to see much of) is the one between Williams and Li. Williams is the favorite, but if Li can stay focused (something she had trouble doing today), it could be a hotly contested match. Sharapova has gone to the Miami finals four time, but has never won the tournament.