Serena Williams has booked a place in the semi-finals of the Madrid Masters following a battling three-set encounter against Anabel Medina Garrigues.

Garrigues fought back after losing the opening set, but it was Williams who edged through with a 6-3 0-6 7-5 scoreline.

Both competitors held their serves well in the opening exchanges of the first set, but Williams began to exert her dominance by snatching a vital break to take a stronghold of the match.

While the number one seed looked likely to cruise through to the final four, Williams was shocked in her opening game of the second set when Garrigues broke her serve and instantly held.

Williams was unable to find her rhythm and crumbled to a 6-0 defeat in the second set, leaving Garrigues with the momentum in the decider.

Both players broke serve on two occasions as the final set went to 5-5, before Williams struck in the 11th game to earn an opportunity to serve for the match.

The world number one raced into a 40-0 advantage, before sealing her place in the last four on her first match point.