London: Estonian Kaia Kanepi is ranked only 80th in the world and had to battle her way through the qualifying competition. Now only unseeded Petra Kvitova stands between her and a place in the Wimbledon semi-finals.
Kanepi provided the shock of the first round when she knocked out Australia`s French Open runner-up Samantha Stosur and has since ghosted into the quarter-finals without dropping a set.
"Kanepi is playing very well right now," said Tuesday`s opponent Kvitova, who upset third seed Caroline Wozniacki in the fourth round.
"We have already played three times. Two I lost and one I won. So we will see. It will be a tough match, but it`s an open match."
Number one seed Serena Williams returns to Centre Court on Tuesday to face China`s Li Na after reversing her 2004 final defeat to Maria Sharapova in the fourth round.
"I think she gives everyone a run for their money," Serena said of her quarter-final opponent. "She`s such a tough player. She never gives up. Right when you have her, she comes back. She`s a player you cannot count out."
In the day`s other quarter-final match-ups, Serena`s sister Venus plays 22-year-old Bulgarian Tsvetana Pironkova while Belgium`s Kim Clijsters, fresh from victory over compatriot Justine Henin, plays 21st seed Vera Zvonareva.