A day after James Duckworth, Adam Walton and Chris O'Connell scored first-round wins, but Thanasi Kokkinakis was beaten, de Minaur was pushed to his limits at the final Masters 1000 event before the US Open at Flushing Meadows.
Having dropped the first set in just 26 minutes, fifth seed de Minaur, who received an opening-round bye, responded to defeat Quentin Halys 1-6 6-3 7-6 (7-4).
The Frenchman had won their only previous meeting, a Miami Masters hard-court clash, back in 2023.
"I've had a couple of battles that recently did not go my way, and I'm glad I was able to kind of dig deep, find myself, and come through a tough battle, which will give me a lot of confidence moving forward," said the 27-year-old Aussie.
De Minaur lost his opening two service games of the match, but was not broken again en route to setting up a round-of-32 clash with Brit Arthur Fery, who saw off Duckworth, 6-4 2-6 7-6 (7-4) in a tick over two-and-a-half hours.
It will be the first clash on tour between de Minaur and the 32nd-seeded French-born Fery.
Earlier on Saturday (Sunday AEST), 25-year-old wildcard Hijikata beat 19th seed Luciano Darderi, of Italy, 6-4 6-2 to set up his last-32 match with 14th seed Jakub Mensik.
Novak Djokovic was beaten in three sets, by Argentine Thiago Agustin Tirante, as was compatriot Miomir Kecmanovic, Hubert Hurkacz, Italian duo Matteo Berrettini and Mattia Bellucci and Denis Shapovalov.
Playing his first match since losing a Wimbledon semi-final to Jannik Sinner, 39-year-old Djokovic struggled in the heat and required a medical timeout in a disappointing US Open tune-up.
"Congrats to my opponent," Djokovic said after losing to the world No.50.
"It was not an enjoyable match for me, for sure. The way I felt. Not the first and I guess not the last time, but it is what it is."
The Serbian — a three-time Cincinnati Open champion and No.5 in the rankings — will look to regroup before heading to New York, where he will seek a record-extending 25th grand slam singles title.
"I think this is the best win of my career," Tirante said.
"I think I really did a good job inside the court. I managed very well the nerves of playing against a legend like Novak."
With Reuters & the AP.
8°C