Ana Ivanovic will draw on lessons from her last Wimbledon clash with Venus Williams when she plays the five-time champion today.

The 21-year-old lost 6-2, 64 to the American in the semi-finals two years ago but is not perturbed.

"I can take a lot from that match," said the No13 seed Serb. "She likes to go for her first shot. She likes to dominate the points.

"Obviously, it will be important for me to serve well because she has great first serves. If I can hold on to my serve and then put pressure on her, that would be a key."

But Ivanovic, who has slipped from the world No1 spot she held last year, is not the only one who will draw on memories of that 2007 match.

Ahead of their fourth-round clash, Williams said: "We had a lot of great exchanges. I remember playing aggressively."

Williams has been playing with her knee bandaged and there are fears that the injury is taking its toll.

Her father Richard said: "She is playing with a very sore knee and needs to put big downward pressure on that knee when she is playing but she can't.

"It's hampering her movement. I think she may have to pull out of the doubles and focus on the singles."