World number one Rafael Nadal has a record-equalling sixth French Open in his sights, but the Spaniard believes undefeated Novak Djokovic will start Roland Garros as title favourite.
Something has got to give over the next two weeks.
Nadal, one triumph away from matching Bjorn Borg's six trophies in Paris has a French Open record of 38 wins and just one loss - his sensational early 2009 exit to Robin Soderling.
Djokovic, the world number two, has won all 37 matches he has played this year and is just five away from matching John McEnroe's 1984 record for successive wins at the start of a year.
It's a streak which has garnered seven titles, including the Australian Open and all four Masters.
"I think Djokovic is the great favourite. He hasn't lost a match since the start of the year and he's playing in an incredible way," said Nadal, who has lost to the Serb in all the four Masters finals.
Crucially, the last two were on the clay of Madrid and Rome where Nadal was defending champion.
But the Spaniard is wary of over-confidence, either by him or his main rival.
"When you arrive at the tournament, every round is difficult. Every match, every time when you go on court you can win and you can lose. So thinking about winning the tournament before the start is, for me, too arrogant."
Djokovic can also snatch Nadal's world number one spot if he reaches the final in two weeks' time.
The Serb is a two-time semi-finalist in Paris, but he is desperate to play down the hype of an event which could see a shift in the sport's balance of power.
"Let us be clear - he is the king of clay, the best ever to play on this surface," Djokovic said about Nadal after his Rome triumph.
The Serb added on Friday, "I don't feel unbeatable; nobody is unbeatable.
"I'm really not trying to think about the run that I have and I'm not trying to think about when this run will end, because that will mean that I'm thinking about losing."
"I say Rafa is the favourite here."
Ever since Djokovic inspired Serbia to their first Davis Cup final triumph in Belgrade in December, he has been unstoppable with his total win streak now standing at 39.
But Nadal has history on his side having defeated Djokovic three times in Paris, all in straight sets.
His 2008 and 2010 surges to the title were achieved without dropping a set and Nadal believes all the pressure will be on Djokovic.
"He beat me in the last four Masters but I beat him in lots of important things in the past -- the semi-finals of the Olympics, the final of the US Open, two semi-finals at Roland Garros," said Nadal.
"We will see what happens. For me it doesn't matter if people think I am more beatable than before."
The fascination with the Nadal-Djokovic duel has left 16-time Grand Slam title-winner Roger Federer in the unusual position of supporting role.
Federer, the 2009 champion, will be 30 in August and is desperate to prove that he is still a threat at the majors.
He is also driven by a desire to recapture the number one spot, where his 285 weeks on top of the rankings is just one week short of Pete Sampras's record.
Federer's three claycourt outings this year have ended prematurely, with a quarter-final loss to Juergen Melzer in Monte-Carlo, a semi-final exit against Nadal in Madrid followed by a third-round defeat to Richard Gasquet in Rome.
Federer has not reached a Grand Slam final since winning the Australian Open in 2010.
"It's not like I'm struggling in the first or second round. It's a new situation with Novak not losing," said Federer.
Andy Murray, too, will be happy to be under the radar in Paris.
The world number four was two points away from defeating a weary-looking Djokovic in the Rome semi-finals and is hopeful of improving on his best Paris performance, a quarter-final run in 2009.