Serena Williams squeaks past Medina Garrigues to reach Madrid Open semifinals

Serena Williams from the U.S. celebrates a point against Anabel Medina from Spain during the Madrid Open tennis tournament, in Madrid Friday, May 10, 2013. (AP Photo/Daniel Ochoa de Olza) (The Associated Press)

Top-ranked Serena Williams overcame Anabel Medina Garrigues 6-3, 0-6, 7-5 on Friday to reach the Madrid Open semifinals.

Williams looked in trouble after failing to win a game in the second set and going 4-2 down in the third. But the defending champion broke the Spaniard's serve twice to pull out the victory.

Second-seeded Maria Sharapova plays Kaia Kanepi in a late quarterfinal.