Not even a comfortable straight-sets start could satisfy Alex de Minaur as the tennis perfectionist led a banner day for Australians at the US Open in New York.
De Minaur was too classy in all departments for Slovakian Andrej Martin, and chiefly too fast around the court as he sped to a 6-4 6-3 7-5 victory in just over two hours on Wednesday.
Open debutant Chris O'Connell and 2018 quarter-finalist John Millman also advanced, giving Australia four players in the second round of the men's draw following Jordan Thompson's victory on day one.
But while O'Connell and Millman were delighted with their performances, de Minaur was feeling ho-hum after his first grand-slam outing since reaching the fourth round last year in New York.
An abdominal strain ruled the 21-year-old out of the Australian Open in January before the tour was shut down for five months because of COVID-19.
"Happy I got the win. It's been a long time coming. I was never going to be perfect," de Minaur said after breaking Martin seven times and dropping serve only twice himself.
"A lot of emotions out there so I'm happy it's over and done with and I can get some good momentum off that and hopefully I can win the the next one and play some better tennis."
The Australian No.1 and 21st seed next faces Richard Gasquet after the veteran Frenchman eliminated 41-year-old Croatian Ivo Karlovic 7-6 (7-0) 7-6 (7-4) 6-3 in his opener.
"I'm definitely going to have to lift my game," de Minaur said.
"He's a very skilled, experienced opponent and he knows how to win matches so it's going to be a very tough one.
"I've got to make sure I'm up for it and I'm very intense and focused the whole match."
O'Connell booked a show-court showdown with Russian third seed and 2019 runner-up Daniil Medvedev with a watershed 4-6 6-4 7-6 (7-2) 6-4 win over Serbian Laslo Djere.
Despite being lower ranked, Millman, who upstaged Roger Federer in the fourth round in 2018 before drawing Rafael Nadal last year, was far too classy for Georgia's No.22 seed Nikoloz Basilashvili.
He won 6-1 6-4 6-4 and meets American Frances Tiafoe next on Friday.
But James Duckworth bowed out with a 4-6 7-5 7-5 6-2 first-round loss to Italian Salvatore Caruso.
HOW THE AUSSIES FARED ON DAY TWO OF THE US OPEN (PREFIX DENOTES SEEDING)
Men's singles, first round:
21-Alex de Minaur bt Andrej Martin (SVK) 6-4 6-3 7-5
John Millman bt 22-Nikoloz Basilashvili (GEO) 6-1 6-4 6-4
Chris O'Connell bt Laslo Djere (SRB) 4-6 6-4 7-6 (7-2) 6-4
James Duckworth lost to Salvatore Caruso (ITA) 4-6 7-5 7-5 6-2
AUSSIES IN ACTION ON DAY THREE
Men's singles, second round:
Jordan Thompson v Egor Gerasimov (BLR) - approximately 3am AEST