Top seed Novak Djokovic and seven-time champion Rafael Nadal were set on a French Open semi-final collision course on Friday, condemning one of the sport's superstars to certain defeat before the final.
The world number one Serb and the third-ranked Spaniard were placed in the same half of the draw, leaving Roger Federer, the second seed, to remain untroubled by either of his two great rivals until the final.
Djokovic, the runner-up to Nadal last year and who still needs a French Open to complete a career Grand Slam, starts against Belgium's David Goffin, who made the last 16 in 2012 after coming through qualifying.
The 22-year-old Belgian took a set off Federer before losing in four sets.
Federer, the 2009 champion who is chasing an 18th major, starts his campaign against a qualifier while Nadal begins against Germany's Daniel Brands.
Nadal, going after an unprecedented eighth French Open title, was seeded three after missing seven months through injury.
But he has been in great form since his return, winning six titles from eight finals.
One of those final losses was to Djokovic at the Monte Carlo Masters.
Friday's proceedings were always going to place Nadal in the path of Djokovic or Federer with the draw given added spice by the withdrawal through injury of world number two Andy Murray and Juan Martin del Potro, the world number seven.
"I am happy to be here at Roland Garros, it's one of the tournaments that I did not want to miss," said Nadal on Friday.
"I love this place. I am healthy to play here another time."
Djokovic could face fast-rising Bulgarian Grigor Dimitrov, the boyfriend of Maria Sharapova, in the third round with compatriot Janko Tipsarevic a likely quarter-final opponent.
Nadal could meet Lukas Rosol in the third round, 11 months after the unheralded Czech dumped the Spaniard out of Wimbledon in a second-round shock which also sent the Roland Garros champion into his seven-month rehabilitation.
In the women's event, top seed Serena Williams, the champion in 2002 and the overwhelming favourite for the title, starts against Ana Tatishvili of Belarus.
Defending champion Sharapova, the second seed, tackles Taiwan's Heish Su-Wei while third seeded Victoria Azarenka, who is scheduled to face Sharapova in the semi-finals, starts against Russia's Elena Vesnina.
Williams, 31, has won her last four tournaments at Miami, Charleston, Madrid and Rome - the last three coming on clay - and has won 24 matches in a row, her best ever run of form.
But she will be wary of Tatishvili, having slumped to a first-round loss to France's Virginie Razzano last year and having only once got beyond the last eight since her 2002 title triumph.
Williams now has 51 career titles and has not lost to Sharapova since 2004.
Fourth seed Agnieszka Radwanska, a quarter-finalist in 2009 and 2010, but carrying a shoulder injury could face sister Urszula in the last 32 if her sibling gets past Venus Williams in her opener.
China's 2011 champion Li Na, seeded six, begins against Spain's Anabel Medina Garrigues and is seeded to face Azarenka in the quarter-finals.