Amelie Mauresmo won the German Open after Venus Williams was forced to withdraw from Sunday's final.

The American's return to action suffered a minor setback as she was forced to withdraw because of a left ankle sprain.

Williams, who had won her previous 15 matches going into the final, injured her ankle while serving for the match in her semi-final win over Karolina Sprem on Saturday.

She had treatment overnight, but was in no fit state to play against Mauresmo.

Speaking on the official WTA Tour site, Williams admitted: "Last night I was still thinking I could play.

"But after having some more treatment this morning, it was obvious I couldn't put any weight on the ankle so I had to make the tough decision to pull out."