By Luke Baker and Ossian Shine
PARIS, June 5 (Reuters) - Roger Federer's gripping four-set victory over friend and compatriot Stan Wawrinka has set up a tantalizing semi-final showdown with clay-court king Rafael Nadal, the 39th meeting between two of the most successful players of all time.
But for Swedish seven-times Grand Slam champion Mats Wilander it's still not the most intense rivalry in this stand out era of men's tennis, during which three of the greatest men's players in history have pushed each other to the limit.
"For sure Nadal and Djokovic," said Wilander when asked which of the rivalries in this phenomenal generation have been the most fascinating.
"I find that Roger and Rafa's, their rivalry has nearly been overshadowed by the two contrasts in style and the fact that they seem to be so completely different when they are on court," the Eurosport commentator told Reuters.
"At one point their rivalry was pretty one-sided, and it seems like it's been pretty one-sided on one side for a period and then the other side for a period... Right now Roger is beating him every time, at least in the last two years.
"So I think that Nadal and Djokovic is probably the most interesting because it's so even and anything can happen on any surface."
Federer, Nadal and Novak Djokovic have won 52 Grand Slam singles titles between them, a total that far outstrips earlier generations of intense rivalry, such as the Pete Sampras and Andre Agassi era of the 1990s, the Bjorn Borg, John McEnroe and Jimmy Connors' clashes of the 1970s and early 1980s, or the Australian domination of Rod Laver and Roy Emerson (NYSE:EMR) in the 1960s.
While Federer has dominated on grass and hardcourts in assembling his 20 Grand Slams, and Nadal has racked up an astonishing 11 French Open championships among his 17, Djokovic is arguably showing the greatest flexibility across surfaces.
"Of course Rafa has an advantage on clay and Novak has an advantage on hard courts, but there's very few matches I walk out there and think, Novak is winning for sure, or Rafa is winning for sure," said Wilander.
Top seed Djokovic will have a chance to earn his place in the semi-finals on Wednesday when he takes on 22-year-old German fifth seed Alexander Zverev on Court Philippe-Chatrier.
Austrian fourth seed Dominic Thiem, 25, will face hard-hitting Russian Karen Khachanov, 23, in the fourth quarter-final.
If Djokovic and Thiem prevail, it will mean the top four men's seeds will face off in the semi-finals -- further cementing the intensity of the rivalry among the top echelon.
NEW GENERATION
But even though this supreme era of competition will naturally end -- Federer looks strong at 37 but few players have managed to compete seriously at 40, while Nadal and Djokovic are 33 and 32 respectively -- another talented generation is emerging and promises to deliver more great rivalries.
Wilander mentioned Greece's Stefanos Tsitsipas and Canada's Denis Shapovalov, both 20-years-old, emerging U.S. star Frances Tiafoe, 21, Zverev and Khachanov among the host of talent with a variety of playing styles who are pushing at the door.
"I think that in a weird way the contrast in styles that are coming up and even in the way that they play, the reason is Roger, Rafa and Novak," he said, saying the extended dominance of those three had shaped the coming generation.
"I actually don't know" who's going to emerge as the next great head-to-head showdown, said Wilander. "But I think the rivalries are going to be really interesting." (Writing by Luke Baker Editing by Christian Radnedge)