Serena hits 20 aces to reach Miami quarterfinals

KEY BISCAYNE, Fla. (AP)â€"Serena Williams rallied from a break down in both sets Monday to beat Samantha Stosur 7-5, 6-3 and advance to the quarterfinals of the Sony Ericsson Open.

Williams, bidding for a record sixth Key Biscayne title, avenged a loss to Stosur when they last met in the U.S. Open final in September.

Ranked 11th, Williams is playing in her first tournament since January after being sidelined by a left ankle injury. She hit 20 aces and lost only six points on her first serve, but she had to rally after being broken in the first game of each set against the No. 5-ranked Stosur.

Williams, seeking her first tournament title since August, has won five consecutive matches when facing top-five players.