Playing his fourth straight night-session match and having endured two-five-setters along the way, the 29-year-old was in no mood to hang around and powered through the first set after absorbing some late pressure on his otherwise solid serve.
The 2020 finalist raced through the next set and staved of a spirited comeback attempt in the third to finish before midnight for the first time this year in New York.
"I don't know what to do with myself, because it's before midnight," said world No.2 Zverev, who pointed to his watch when the match ended at around 11.48pm (local time).
"I might go to a practice court, or a bar ... that was a joke, so relax. I'm feeling happy, compared to the first two matches the level has been going up."
After seeing off the 21st seed, Zverev, the defending French Open champion, became the only man to reach the quarters at all four grand slams this year.
His fifth quarter-final at the tournament will be against Botic van de Zandschulp after the Dutchman outlasted Arthur Gea 3-6 6-7 (0-7) 7-6 (9-7) 7-6 (7-3) 6-4 in five hours 13 minutes, the fourth-longest match in US Open history, earlier on Monday (Tuesday AEST).
Gea, a Frenchman who got in the tournament when 2022 runner-up Casper Ruud pulled out with a back injury, had a match point in the third-set tiebreaker in a bid to become the first lucky loser to reach the quarters of a men's major.
"I think this is probably better than the first quarter-final I made here," van de Zandschulp said.
"It hasn't sunk in yet, but I think tomorrow, it's going to be a great feeling."
Also going five sets — though a mere three hours 50 minutes — was Karen Khachanov's 7-5 4-6 6-7 (8-6) 6-1 6-4 victory over 14th seed Learner Tien.
Tien, 20, was trying to give the host country four men in the US Open last eight for the first time since five made it in 1995. No.8 Ben Shelton, No.11 Frances Tiafoe and Alex Michelsen all advanced on Sunday.
And Alexander Blockx, the 28th seed, beat Argentina's 24th-ranked Francisco Cerundolo 6-3 4-6 7-5 7-5 to become the first man from Belgium to reach the US Open quarter-finals, where he will play Russian Khachanov.
"It was unreal, to be honest," Blockx said on court after the match about being on Arthur Ashe Stadium.
"This morning, I stepped on this court for the first time to warm up and that felt unreal already. So playing a match here, winning a match here, is crazy."
With Reuters.
