Maria Sharapova retires from WTA Tokyo quarter-finals

Maria Sharapova had to retire from her Pan Pacific Open quarter-final in Tokyo against Petra Kvitova when she twisted an ankle during the first set. Sharapova was trailing 4-3 in the first set when she sprained her left ankle and the pain was too much for the Russian to continue.

"I hit a serve then landed awkwardly on my left ankle. I felt a sharp pain and next thing I knew I was on the floor. It swelled up immediately and I knew there was no way I could continue," Sharapova said. "I will go straight to the hospital and get an MRI scan. I don't know how bad it is. I hope I can finish the season."

"I was really looking forward to this match, to be playing Petra after I lost to her at Wimbledon. There's not much more I can say right now. I'm sorry for the tournament and for my Japanese fans that the match had to end this way. I am incredibly disappointed and in a lot of pain."

It's a big blow for Sharapova who was hoping to get revenge on Kvitova for her defeat in the Wimbledon final and also put pressure on Caroline Wozniacki for the world number one ranking. The Dane will have lost a lot of points after falling in the third round while attempting to defend her title this week.

Kvitova will be delighted to have reached the semi-finals of a WTA Premier event after a dismal run since she won Wimbledon, suffering early losses in virtually every single event she's entered. However the Czech is looking much happier this week and she takes on Vera Zvonareva for a place in the final.