Miami - Russian third seed Maria Sharapova advanced to the semi-finals of the WTA and ATP Miami Masters hardcourt tournament with a 7-5, 7-5 victory over Italian eighth seed Sara Errani on Wednesday.
Sharapova fired six aces but made 14 double faults before saving a break point in the 10th game of the second set.
She then broke Errani in the penultimate game and held serve to end it on a forehand winner after just under two-and-a-half hours.
Four-time Grand Slam champion Sharapova will play for a spot in the final against Serbian 22nd seed Jelena Jankovic.
Results on Wednesday from the eighth day of the $8.5 million WTA and ATP Masters Miami hardcourt tournament (x denotes seeding):
David Ferrer (ESP x3) bt Jurgen Melzer (AUT) 4-6, 6-3, 6-0
Tommy Haas (GER x15) bt Gilles Simon (FRA x11) 6-3, 6-1
Maria Sharapova (RUS x3) bt Sara Errani (ITA x8) 7-5, 7-5
Jelena Jankovic (SRB x22) bt Roberta Vinci (ITA x15) 6-4, 6-7 (6/8), 6-3