Wimbledon: Not so much a warm-up act as clash of tennis Titans as Novak Djokovic and Roger Federer do battle A DREAM semi-final pitching two of the game's greatest players against each other is likely to be a tasty warm-up act for many of the fans in Centre Court today as home favourite Andy Murray bids to reach a maiden Wimbledon final. World No 1 Novak Djokovic takes on 16-times grand slam champion Roger Federer in a mouth-watering encounter - which surprisingly will be the first time the pair have met each other on grass in what is their 27th match - that would have graced any court on any occasion. The mention of both names together is usually enough to have tennis fans salivating in anticipation. As it is, both players could play second fiddle to a Briton with no grand slam titles as he faces Frenchman Jo-Wilfried Tsonga. After Rafa Nadal's shock exit in the second round to Lukas Rosol, it would be understandable for Djokovic and Federer to have a sense of relief that whoever prevails from their battle will not have to face the Mallorcan with 11 slams in a Centre Court showdown on Sunday. The Serb will be going into today's tussle with the psychological edge as he has swatted aside the Swiss magician in six of their past seven encounters, the most recent being at the French Open four weeks ago. Their meeting at the US Open last year, when Federer led by two sets before Djokovic stormed back to win in five, is also likely to be fresh in his memory. "I don't feel that any match is over against a top player like Novak is," Federer said after ruthlessly dispatching Mikhail Youzhny in straight sets in his quarter-final on Wednesday. With his ability of his shot-making, you know the match is never over until the umpire calls the score. Among the unknowns, however, is how these two will match up on grass and on a court where six-times champion Federer ruled the roost for so many years. There have been 26 meetings between the two, with Federer leading 14-12 overall, but Wimbledon's manicured lawns will play host to the spectacle for the first time. He uses his serve very well. He opens up the court. He uses that slice really well to get the balls to bounce low. He's very aggressive at times. He can defend well. He has a really smart game for this surface," Djokovic said after his own quarter-final romp against Florian Mayer. But I improved playing on grass in last couple of years. I mean, I won the title here last year, got to another semi-final this year, so I'm feeling good about this surface, about myself on the court. I really have nothing to lose. Federer will set out in pursuit of perfection and believes anything less will see him punished by the defending champion. Federer can reclaim the world No 1 ranking from Djokovic by claiming his seventh Wimbledon title. Another triumph would take him level with Pete Sampras and William Renshaw, who reigned in the 1880s, in terms of Wimbledon successes, and the ranking move would mean him matching Sampras" record of 286 weeks at the top. There is a large step to take before he can give serious consideration to either achievement though, and Djokovic has no intention of giving up his hard-earned title or his ranking. "You have to prepare yourself well in every department," Federer said. Only a perfect performance will be enough to beat Djokovic.