WATCH the US Open from the quarter-finals onwards LIVE, FREE and in HD on SBS from 2am (AEST) Wednesday September 9 or live stream via SBS On Demand here.
Australia's best hope Alex de Minaur powered into the third round with a four-set win (6-4, 6-3, 6-7, 7-5) over French veteran Richard Gasquet.
It wasn't all good news for Australia, though, as John Millman fell in five sets against American young gun Francis Tiafoe (7-6, 3-6, 1-6, 6-3, 6-3) and Chris O'Connell was eliminated by third seed Daniil Medvedev (6-3, 6-2, 6-4).
In the women's draw, second seed Sofia Kenin (this year's Australian Open winner) coasted past Canadian Leylah Annie Fernandez in straight sets (6-4, 6-3) and third seed Serena Williams advanced 6-2, 6-4 through Margarita Gasparyan.
Canadian young gun Felix Auger-Aliassime made a statement belting former champ Andy Murray in straight sets (6-2, 6-3, 6-4), in what could be a symbolic changing-of-the-guard match.
In other big matches, men's second seed Dominic Thiem made light work of Sumit Nagal, winning in straight sets (6-3, 6-3, 6-2), powerful Italian Matteo Berrettini (sixth seed) also progressed in three.
It was a strong day for America's women in the draw, with Madison Keys (seventh seed), Sloane Stephens and Amanda Anisimova joining Kenin and Williams in the third round.