Injury-prone Thanasi Kokknakis dropped a scheduling bombshell on Day 4 at the US Open as the Australian pulled out prior to his second-round match against Rafael Nadal on Thursday.
The second-seeded Spaniard benefitted from the walkover and reached the third round without firing a shot.
Wild card Kokkinakis, who blamed a longstanding shoulder problem which has affected him for much of his patchy career, had been hoping to reach the third round of a major for the first time since Paris, 2015.
Meanwhile, controversial talent Nick Kyrgios scored an Aussie victory as he hammered Antoine Hoang of France 6-4, 6-2, 6-4.
No. 5 Daniil Medvedev, whose on-fire game this month took him to a pair of hardcourt finals and the Cincinnati Masters title, continued to dominate, beating Hugo Dellien 6-3, 7-5, 5-7, 6-3.
Alexander Zverev successfully came through a second straight five-set test as the German sixth seeded got past Frances Tiafoe 6-3, 3-6, 6-2, 2-6, 6-3 in just over three hours.
Zverev struggled in the opening round as well, going the full distance to start off his Grand Slam fortnight.
Victory over the American gives Zverev a solid 4-1 lead in their career series, with the winner reach the third round here for a second consecutive year.
Tiafoe’s modest record against Top 10 opposition took another hit as he lost his 15th of 18 played against the elite.
2016 title-winner Stan Wawrinka advanced in straightforward fashion, beating Frenchman Jeremy Chardy 6-4, 6-3, 6-7(3), 6-3.
The Swiss who owns trophies at three of the four majors was unable to close out victory as Chrdy saved a match point in the penultimate.
But the 34-year-old put the hammer down a game later, firing a winner deep into the corner on the first of three additional winning chances.
Wawrinka now stands a perfect 6-0 in the series.
“It was a great battle,” the winner said. “I served well, played aggressive and stayed with him.
I’m happy to go through and close out the match in four sets.”
Rising Australian Alex di Minaur was ruthless with Christian Garin, eliminating the Chilean 6-3, 7-5, 6-3; Belgian 15th seed defeated French qualifier Gregoire Barrere 6-2, 6-2, 6-2.
Briton Dan Evans set up a third-round meeting with second seed Roger Federer after putting out France’s Lucas Pouille 6-4, 6-3, 6-7(4), 6-4.
Aljaz Bedene needed more than four hours to stage a massive comeback form two sets to love down, overturning a lead by Frenchman Benoit Paire for a 4-6, 6-7(3), 6-2, 7-5, 7-6(4) triumph.
The marathon left Paire depleted and furious at the end, with the loser rushing off court so fast that the traditional handshake with the chair umpire went by the wayside.
Canadian Denis Shapovalov advanced over Finnish-born Swiss Henri Laaksonen 6-4, 7-6(2), 6-2.