Roger Federer takes on Novak Djokovic this afternoon in the semi-finals of Wimbledon 2012 (13:10 BST start).
This afternoon's clash is the first meeting on grass between the pair. It promises be to be an enthralling prospect, and there's much at stake. If Federer goes on to win a seventh Wimbledon title on Sunday, then he will return to the top of the world rankings and thus have the chance to break Pete Sampras' all-time record of 286 weeks at the top spot (Federer himself has spent 285 weeks so far as world number one).
Djokovic has dominated Federer on clay in recent years, beating the Swiss in straight sets in the French Open semi-finals last month. However Federer will feel he has a much greater chance on grass where his serve is most effective and he can fully utilise his superb volleying ability.
He will be encouraged by the quarter-final results as while he crushed Mikhail Youzhny for the loss of just five games, Djokovic looked vulnerable at times during his 6-4 6-1 6-4 win over Florian Mayer.
Djokovic is relishing the challenge of playing Federer on grass for the first time.
"I am looking forward to it," he said.
"It's always a pleasure playing him. He is a great champion. He has dominated for so long. He is so consistent and for me it will be the ultimate challenge. This is where he won six titles. He definitely wants to prove himself and to everybody else that he can win it once again."
"We both have to play at our best in order to get a win. I really have nothing to lose. I'm going to try to win."
This one really could go either way and has the potential to be a classic.
Prediction: Federer in five.