Novak Djokovic set up a semi-final against Stefanos Tsitsipas at the French Open as he came from behind to defeat Pablo Carreno-Busta in four sets.
Djokovic had tape on his neck and looked to be having some issues with his left arm while losing the opening set, the first he has dropped at this year's tournament in Paris.
But the world number one appeared less troubled thereafter as he fought back to get past Carreno-Busta 4-6 6-2 6-3 6-4 in a high-quality contest lasting three hours and 10 minutes.
The Spaniard was Djokovic's opponent when he was sensationally disqualified from the US Open last month after hitting a ball in frustration that struck a line judge.
That is the only match in 37 this year that has not ended in victory for the Serbian 17-time grand slam winner, who is aiming at Roland Garros to add to his 2016 triumph, his sole French Open title to date.
Tsitsipas earlier roared into the last four with a three-set demolition of Andrey Rublev.
Russian Rublev, the 13th seed, was seemingly in control during the opening set, leading 5-3 with Tsitsipas serving to stay in it.
Four games later Rublev had lost the set, and barely over an hour later he had lost the match, winning only five more games as he was sent packing.
What looked on paper another potential five-setter turned into a 7-5 6-2 6-3 procession for the Greek fifth seed.
Tsitsipas said: "I've been feeling really comfortable on this court and despite a bad start and being a break down I remembered what a big fighter I am.
"It's about fighting and trying to find solutions at difficult moments. I managed to get my brain working and found solutions.
"Roland Garros is a tournament I have been watching since I was a kid and always dreamed of playing on these courts.
"I used to skip classes at school to watch it. That's how much I like this tournament. It's a dream come true playing here and in front of the public."
The other last-four clash, claycourt master Rafa Nadal passed his first real test of this year's French Open with a 7-6(4) 6-4 6-1 victory against Italian rising star Jannik Sinner as his quest for a record-breaking 13th title gathered momentum on Tuesday night.
The Spaniard, also looking to match Roger Federer's record of 20 Grand Slam men's singles titles, was stretched like rarely before by the 19-year-old Sinner as he set up a clash with Argentine Diego Schwartzman, who beat him in the Italian Open quarter-finals last month.
The 34-year-old Nadal's 97 previous victories at Roland Garros made the difference in the key moments with the Spaniard rallying from a break down in the first two sets.
Sinner, the first French Open debutant to reach the last eight since Nadal in 2005, confirmed his immense potential but lacked just a bit of composure when it mattered.
