Australia’s John Millman has been edged out of the Western and Southern Open in New York after going down 4-6 7-6 (7-3) 7-6 (7-5) to big-serving American John Isner.
In a second round clash that lasted over two-and-three-quarter hours, the giant world No.21 hurled down 35 aces against the Queenslander who held his serve throughout at the Billie Jean King National Tennis Centre.
World No.1 Novak Djokovic battled through neck pain that forced him to withdraw from his doubles match on Sunday to squeeze past Lithuanian qualifier Ricardas Berankis 7-6 (7-2) 6-4.
He will now meet American Tennys Sandgren in the third-round.
“Obviously I wasn’t close to my best with serving but when I needed a good serve, I found it,” said Djokovic.
“The injury is not so bad that I have to pull out from singles but it’s bothering me definitely with the serve. But it’s getting better.”
Third-seeded Russian Daniil Medvedev launched the defence of his title with a tidy 6-4 6-4 second round win over Marcos Giron.
The subdued atmosphere and empty stands were far removed from a year ago when Medvedev entertained a capacity crowd with a startling fight back in the US Open final against Rafael Nadal before falling to the Spaniard in five-sets.
Playing in the shadow of the massive Arthur Ashe Stadium that will be centre stage when the US Open gets underway next week, Medvedev delivered a workmanlike effort against the 101st ranked American on a Grandstand court, left empty by COVID-19 safety protocols.
Medvedev was rarely under pressure, saving all three break chances he faced while getting the one early break he needed in each set for an uncomplicated win.
The world No.5 will next take on Slovenian qualifier Aljaz Bedene, who was 7-6 (7-5) 7-5 winner over American Taylor Fritz.
Canadian Milos Raonic blasted 23 aces in 6-3 7-5 victory over Briton Daniel Evans.
He will now meet former world No.1 Andy Murray, who recorded his first top-10 victory in over three years with an impressive 6-3 3-6 7-5 triumph over world No.7 Alexander Zverev.
Murray, who played his first official match since last November on Saturday, had been hampered by a pelvic injury that forced him to miss the start of the 2020 season.
Murray is now down to 134 in the rankings having gone through two hip surgeries.