Frenchman Gael Monfils beat top-seeded Marin Cilic 6-3, 7-6(8) on Thursday to advance to the quarter-finals of the Rio Open in Brazil.
Rain forced the clash to be suspended at a crucial stage on Wednesday, with the pair deadlocked at 7-7 in a tie-break after Monfils won the opening set 6-3.
Monfils then finished Cilic off in 5 minutes when they returned on Thursday to set up a quarter-final clash with Argentinian Diego Schwartzman.
“I don’t think I feel very good, it’s not about numbers,” Monfils said. “I think I’m not in my best shape yet, I’m fighting for every point. Tomorrow (Friday) will be a great match, Schwartzman is a very fast player. I will have to play more aggressive.”
Croatia’s Cilic won only one match on the clay in Rio in his first tournament since he reached the Australian Open final in January.
In the other match, defending champion and second seed Dominic Thiem eased through to the quarters following the retirement of opponent Pablo Andujar, who was trailing 4-2 in the first set.
Next up for Thiem is eighth seed Fernando Verdasco after the Spaniard rallied past Nicolas Kicker 6(3)-7, 6-2, 6-0.
Fourth-seeded Fabio Fognini also advanced with a 4-6, 6-4, 7-6(6) victory against American Tennys Sandgren.
The Italian will face Slovenian Alijaz Bedene, who eliminated third seed Pablo Carreno Busta of Spain with a 6-2, 5-7, 6-2 win.