Rafael Nadal comes face-to-face with the future in the shape of Jannik Sinner for a place in the Roland Garros semi-finals on Tuesday.
Victory for the 12-time champion could set up another Paris clash with Dominic Thiem who he has defeated in the last two finals.
However, third seed Thiem must first get past dangerous opponent Diego Schwartzman.
AFP Sport looks at the two quarter-finals:
Diego Schwartzman (ARG x12) v Dominic Thiem (AUT x3)
Head-to-head: Thiem leads 6-2
-- Thiem arrived in Paris having captured his first Grand Slam title at the US Open and had made serene progress in the first three rounds until being given a huge scare in the last 16 by France's world 239 Hugo Gaston who pushed him to five sets and three and a half hours of toil.
"Since I was a young kid, I always did pretty well in pressure situations," said Thiem.
Ten of the 27-year-old Austrian's 17 career titles have come on clay.
He has made at least the semi-finals in Paris for the last four years, losing to Nadal in the 2018 and 2019 finals.
Nadal also got the better of him in the 2017 semi-finals while he went down to Novak Djokovic, also in straight sets, in the last four in 2016.
Thiem has beaten Schwartzman in three of the pair's four clay court meetings but the 5ft 7in (1.70m) Argentine defeated Nadal in the Rome quarter-finals on the eve of the French Open before losing to Djokovic in the final.
The 28-year-old fan of Boca Juniors and reggaeton music has three career titles, two on clay.
Schwartzman has yet to drop a set on his way to a second quarter-final in Paris and his fourth in all at the Slams.
Paths to quarter-finals:
1st rd: bt Miomir Kecmanovic (SRB) 6-0, 6-1, 6-3
2nd rd: bt Lorenzo Giustino (ITA) 6-1, 7-5, 6-0
3rd rd: bt Norbert Gombos (SVK) 7-6 (7/3), 6-3, 6-3
4th rd: bt Lorenzo Sonego (ITA) 6-1, 6-3, 6-4
1st rd: bt Marin Cilic (CRO) 6-4, 6-3, 6-3
2nd rd: bt Jack Sock (USA) 6-1, 6-3, 7-6 (8/6)
3rd rd: bt Casper Ruud (NOR x28) 6-4, 6-3, 6-1
4th rd: bt Hugo Gaston (FRA) 6-4, 6-4, 5-7, 3-6, 6-3
Jannik Sinner (ITA) v Rafael Nadal (ESP x2)
Head-to-head: First meeting
-- Nadal has made the quarter-finals for the 14th time, dropping just 23 games in four rounds despite his pre-tournament prediction that he was facing his toughest ever Roland Garros due to the slow autumn conditions and the new, heavier balls.
His form is hard to gauge as his opponents have been ranked 83, 236, 74 and 213.
The 34-year-old Spaniard can equal Roger Federer's record of 20 Grand Slam titles with victory next weekend.
However, standing in his way is Sinner, the Italian 19-year-old who has made a mockery of his world ranking of 75 to become the youngest men's Grand Slam quarter-finalist since Novak Djokovic in Paris in 2006.
On his way, he has knocked out Belgian 11th seed David Goffin in the first round followed by a last-16 defeat of German sixth seed and US Open runner-up Alexander Zverev on the back of 39 winners.
Sinner, a champion skier in his youth before opting for tennis, is also the first player to reach the last eight on his Roland Garros debut since Nadal lifted the trophy in 2005.
"It's not the easiest thing to play Nadal at Roland Garros. The record he has here, I think nobody can beat that. He is super confident," said Sinner who now has two top 10 wins after beating Stefanos Tsitsipas in Rome.
Paths to the quarter-finals:
1st rd: bt David Goffin (BEL x11) 7-5, 6-0, 6-3
2nd rd: bt Benjamin Bonzi (FRA) 6-2, 6-4, 6-4
3rd rd: bt Frederico Coria (ARG) 6-3, 7-5, 7-5
4th rd: bt Alexander Zverev (GER x6) 6-3, 6-3, 4-6, 6-3
1st rd: bt Egor Gerasimov (BLR) 6-4, 6-4, 6-2
2nd rd: bt Mackenzie McDonald (USA) 6-1, 6-0, 6-3
3rd rd: bt Stefano Travaglia (ITA) 6-1, 6-4, 6-0
4th rd: bt Sebastian Korda (USA) 6-1, 6-1, 6-2