The mother of all tennis rivalries will once again make a comeback on the hallowed grass of Wimbledon. Two of the most successful men's tennis players ever will lock horns with each other in a much-anticipated semifinal on the Center Court on Friday.

Roger Federer is gunning for his ninth title at the All England Club and seeking to extend his all-time record of 21 Grand Slam singles, while Rafael Nadal is eying his third piece of silverware at SW19 to add to his own overall Grand Slam tally of 18.

The big ticket clash between the two titans is more than a duel or a gladiatorial combat per se. A Federer versus Nadal match can be best viewed as a duet than a duel. If a sublime Federer is poetry in motion, a resilient Nadal is always like powerful prose intertwined with staccato bursts. It's a spectacular visual treat for any tennis connoisseur and unbridling delight for a diehard fan who often forgets to take sides. It's often a one-of-its-kind rivalry where a tennis aficionado returns home with the mesmerizing tennis memories irrespective of who wins or loses. A face-off between the two is not just a match but a grand performance and an opulent opera, where the two continuously and effortlessly shuffle between the roles of playing a tenor and a bass.

Their latest clash for the crown has rekindled the memory of one of the epic battles in the history of world tennis. Eleven years ago, a much younger Federer was outlasted by a gung-ho Nadal in a marathon clash that ended 6-4, 6-4, 6-7 (5/7), 6-7 (8/10), 9-7 as the clock ticked past 9 p.m. on Center Court.

Over a decade has passed since then, but the duo continued to remain active in the fantasy of their fans worldwide, even though age seems to have caught up a bit with them without reducing their appetite for more wins or lessening their hunger for more titles. Now they have an incredible 38 Grand Slam titles between them and more than 100 million U.S. dollars in prize money each. But they continued to remain the biggest and the most famous performers with the racquet.

Since their first-ever face-off at the 2004 Miami Masters, the duo have played each other 39 times. Nadal, who won that maiden clash in the round of 32 tie in Miami, is leading the head-to-head numbers with 24 wins to Federer's 15. Their Grand Slam record is also in Nadal's favor with 10 wins whereas Federer has beaten his arch-rival only thrice in the past. However, the serve and volley game on grass helped Federer go one up at Wimbledon with the eight-time champion winning twice at the All England Club with Nadal's sole win coming in that historic 2008 match.

The undisputed king of clay, Nadal may not have bagged more than two titles at the year's third and the most prestigious major but he did break Federer's long and unbroken-winning streak to deny him a 6th successive Wimbledon title in 2008. The Spaniard added another in 2010 after his Swiss rival regained the silverware in 2009.

Since edging past Federer to win his record 12th title at Roland Garros last month, the 33-year-old defending French Open champion is well poised to turn the clock against his struggling 37-year-old rival with the stage set for yet another tantalizing tennis spectacle.