Fifth seed Alexander Zverev overcame a slow start to dispatch France's Adrian Mannarino 6-7(4) 6-4 6-2 6-2 in a match that was delayed by health officials for over two-and-a-half-hours.
The third-round US clash was originally scheduled to start at 2:30pm local time on Louis Armstrong Stadium, but was pushed back while the United States Tennis Association conducted a "collaborative dialogue" with health officials.
Mannarino was placed under an "enhanced protocol plan" after coming in contact with fellow Frenchman Benoit Paire, who pulled out of the tournament having tested positive for COVID-19.
When the players finally arrived on court at 5:15pm, Mannarino claimed the opening set in a tiebreak as an untidy Zverev posted 26 unforced errors.
But the German rediscovered his rhythm in the second set to find a way past Mannarino's serve in the 10th game, unleashing a blistering forehand winner to get to one set apiece.
With momentum on his side, Zverev converted a further five break points opportunities to book a last-16 spot for the second consecutive year in New York.
"Well I guess I dont know if you guys know, but he was around [Benoit] Paire [who tested positive the day before the tournament]," Zverev revealed after the match.
"I guess New York state called and said he should't play, so it was back and forth and back and forth and it was political - it was not us players - we were just sitting around."
"I was told that there is very little chance that we're going play.
"They said there is a chance at 5pm, but yeah I was just kind of waiting around and seeing.
"Obviously for me as a player and for a fellow player, I am happy he was able to play, but in the beginning I was a little bit cold I would say.
"Its also different - I mean we were supposed to play during the warmest time of the day - I strung my rackets a little bit tighter and I prepared for the balls flying a little bit more, and then we came out here and we played basically a night match, so yeah, it was different."
Denis Shapovalov won the battle of North American young guns by grinding out a 3-6 6-3 4-6 7-6(5) 6-2 win over Taylor Fritz to move into the fourth round.
The match played out exactly as one would expect from two of tennis's rising talents, with the 12th-seeded Canadian Shapovalov and 19th-seeded American Fritz engaged in a seesaw tussle.
The entertaining three-and-a-half-hour match in an empty Arthur Ashe stadium, ended with 21-year-old Shapovalov back in the last 16 at Flushing Meadows for the first time since he made his US Open debut in 2017.
"I was struggling serving because he was putting his racket on everything and he was playing so solid," said Shapovalov.
"In the fourth set when I was down a break I was able to loosen up and got the rhythm back on my serve.
"I was really happy with the way I served especially that last set."
The big-serving Fritz had a chance to serve out the match at 5-3 in the fourth, but Shapovalov grabbed the break he needed to drag the set to a tiebreak which he won.
Recharged by his rally, it was the Canadian who raced ahead 3-0 in the fifth before closing out the contest with another break when Fritz's return sailed long.
Next up for Shapovalov is Belgium seventh seed David Goffin who was a 6-1 7-6(5) 6-4 winner over Serbia's Filip Krajinovic.
World number one Novak Djokovic produced a dominant display to put away German Jan-Lennard Struff 6-3 6-3 6-1, extending his winning streak to 26 matches in 2020.
Meanwhile, Dan Evans became the final Briton to be knocked out of the singles draw after he suffered a 4-6 6-3 7-6(5) 7-6(1) defeat by Frenchman Corentin Moutet.
The result was followed by fellow Briton Cameron Norrie's 7-6(2) 4-6 6-2 6-1 loss to Spaniard Alejandro Davidovich Fokina.
