There were early disappointments for the Americans as a couple of ‘star’ players lost to unseeded opening round opponents.
Venus Williams, a two-time finalist at this event, was sent packing by in-form Swiss Belinda Bencic with a 6-3, 7-5 boilover on Rod Laver Arena, leaving the tournament without a Williams sister in the second round for the first time in 21 years.
“I think she played well,” said Venus Williams.
“I don’t think I played a bad match. She just played above and beyond. I just have to give her credit for that.”
In the other match, US Open champion Sloane Stephens was another big name who failed to progress beyond the first round.
The 13th-seeded American, now winless in eight attempts since her surprise maiden Grand Slam triumph last September, went down in flames on Monday, falling to China’s Zhang Shuai 2-6 7-6 (7-2) 6-2 on Monday.
The 24-year-old Stephens, however, remained upbeat. Speaking after the match, she said: “Even though I lost, I’m not too sad. Everything is good. Relax, everybody. It will be OK. Don’t worry. We will get back to having fun soon.”
“Just give me a little bit to regroup and we will be OK.”
Last year’s semi-finalist CoCo Vandeweghe was also sent packing from the Australian Open in the first round on a horror day for American women.
Vendeweghe, who also made the last four at the US Open in 2017, was knocked out by Hungary’s Timea Babos 7-6, 6-2 in an hour and 46 minutes.
She was the third American big name to fall on day one of the year’s opening Grand Slam after Williams and Stephens.
In the Men’s Singles, last year’s US Open finalist, Kevin Anderson got knocked out by Kyle Edmund in five sets.
Edmund, who’s the only British man in the Singles draw, won 6-7 (4-7) 6-3 3-6 6-3 6-4 in the opening round in Melbourne.
World no. 1 Rafael Nadal, home favourite Nick Kyrgios will be in action this Monday morning.