Serena Williams is on track for a quarter-final meeting with Caroline Wozniacki after beating Samantha Stosur 7-5 6-3 in the Sony Ericcson Open last 16.
The American had to come from a break down to take the first set from her Australia opponent, who was seeded number six for the tournament in Miami.
The pair then exchanged games on serve during the opening stages of the second set but Williams got the break that saw her serving for the match.
Stosur took a 40-0 lead on the Williams's serve but the 13-time Grand Slam champion, who served well throughout the contest, came back to take the match and progress into the last eight.
She will play former world number one Wozniaki, should the Dane beat Yannick Wickmayer later this evening.