World number one Andy Murray will face up-and-coming Russian Karen Khachanov in the fourth round of the French Open at about 11:30 BST on Monday.
Top seed Murray, 30, is trying to reach the last eight in Paris for the sixth time in the past seven years.
Khachanov, 21, is ranked 53rd and plays his first Grand Slam last-16 match after beating American John Isner.
“Mentally I feel pretty good just now,” Briton Murray said after beating Juan Martin del Potro in round three.
Having struggled with fitness and form during much of the year, the Scot played superbly to see off the Argentine in straight sets on Saturday.
“After each round, I’m not thinking about winning,” he said.
“I didn’t come here with the mindset that I’m definitely going to go a long way.
“I was going to try and just get through the first round and hopefully feel better each day. That’s been the case so far.”