The opponent for the No. 6 seed will be 55th-ranked John Millman of Australia who stunned Roger Federer 3-6, 7-5, 7-6 (7), 7-6 (3).
There was that sort of respite during No. 20 Naomi Osaka's 6-3, 2-6, 6-4 win against No. 26 Aryna Sabalenka, a matchup between two powerful players seeking a first Grand Slam quarterfinal appearance.
Not since Pat Rafter handed a tantrum-throwing Federer a tennis lesson on the then-18-year-old's grand slam debut at Roland Garros in 1999 had an Australian conquered the great Swiss at a major.
"I'm probably in a little bit of disbelief", Millman, 29, said after three hours and 35 minutes in the cauldron of Arthur Ashe Stadium.
"I've got a lot of respect for Roger". The feet weren't moving.
John Millman, an unknown Australian in the first round of 16 Grand Slam match of his 12-year career, spoiled the party.
'But I got out of a tough second set and really found my feed, made a decision to be a little bit more aggressive.
Millman, who trained with Federer in Switzerland before the grass-court season, was in shock at having beaten one of his idols.
Millman fought back from being down a break early in the fourth set to force a tiebreak.
During lengthy exchanges from the baseline, Sharapova often blinked first, although a couple of times the righty managed to switch her racket to her left hand for a desperation shot to extend a point. Federer served 10 double faults and committed a frankly staggering 76 unforced errors throughout the match, which helped pave the way for easily the biggest win of Millman's career. He was manipulating me around the court, " Millman said. Coming off his triumph at Wimbledon, he has reached the final eight at Flushing Meadows for the 11th time.
The other quarterfinal on the bottom half of the draw will be 2014 runner-up Kei Nishikori against 2014 champion Marin Cilic or No. 10 David Goffin.
The first Portuguese player to reach the fourth round of any grand slam, the 68th ranked Sousa never looked a threat to progress any further as his magical US Open run came to an end.
He improved to 28-0 at the U.S. Open against opponents ranked outside the top 50, and here's another reason it wasn't all that surprising the way things went Monday: Djokovic is now 5-0 against Sousa, taking all 14 sets they've played against each other.
Both Nishikori and Djokovic missed last year's U.S. Open with arm injuries.
"I don't have any pressure, " said Nishikori, who was so crushed about missing the US Open past year that he couldn't even watch the tournament.