Rafael Nadal took the roundabout route again before defeating Nikoloz Basilashvili to set up a quarter-final clash with Dominic Thiem at the US Open.
Georgian Basilashvili had won just a single game against Nadal in their only previous meeting at the French Open last year, but played superbly here to take a set before going down 6-3 6-3 6-7 (6/8) 6-4 after three hours and 18 minutes.
Basilashvili thumped 56 winners compared to 30 for Nadal, but the Spaniard's greater consistency ultimately saw him through to face Thiem, the only man to beat him on clay for the last two years.
Nadal said: "Two matches in a row very tough ones. I had a big chance at the beginning of the third, if I make that break, maybe things will be different. But I didn't.
"I think I played a good tie-break, but he played fantastic. A lot of credit to him. He was playing great, hitting the ball very, very strong. It seems like I was not in control of the point even when I was hitting good shots.
"I'm very happy to be through. I think I did what I have to do. It's a big victory for me because of what happened two days ago. The physical issue was there of course, but I feel good."
There was no sign of the strapping under his right knee that had caused agitation during Nadal's four-hour marathon against Karen Khachanov on Friday.
Nadal will face Dominic Thiem, who knocked out last year's finalist Kevin Anderson to reach the last eight for the first time.
The Austrian ninth seed was denied a place in the last eight 12 months ago by a remarkable comeback from Juan Martin del Potro but exorcised his demons in impressive fashion to win 7-5 6-2 7-6 (7/2).
Anderson, who also reached the Wimbledon final, had battled through two five-set matches at Flushing Meadows but had no answer to Thiem.