Albert Ramos-Vinolas won the last four games to beat fifth-seeded Marin Cilic of Croatia 6-2, 6-7 (5), 6-2 and reach the Monte Carlo Masters semifinals on Friday.
Cilic, the 2014 U.S. Open champion, seemed to be in command when he broke at the start of the third set. But the Spaniard rallied to set up a semi against 11th-seeded Lucas Pouille of France or No. 16 Pablo Cuevas of Uruguay. They were playing their match later Friday.
In other quarterfinals, defending champion Rafael Nadal faced unseeded Diego Schwartzman and second-ranked Novak Djokovic played David Goffin.
Ramos-Vinolas needed 2 1/2 hours to win, but could have got there faster after leading 5-3 in the tiebreaker — only for Cilic to level the set score with a volley that only just landed in. He puffed his cheeks in relief.
Cilic won their only previous match on clay five years ago in Hamburg, Germany, but the Spaniard looked sharp here early on. He broke Cilic in the third game and clinched the first set when Cilic's cross-court backhand went out.
Ramos-Vinolas won on his first match point when Cilic double-faulted.