Tennis: ASB Classic champion Coco Gauff breezes through first round of Australian Open against Slovak Anna Karolina Schmiedlova

Fourth seed Coco Gauff has made a slightly wobbly start to her Australian Open campaign, before the American found her rhythm to defeat Slovakia's Anna Karolina Schmiedlova 6-3 6-0 and reach the second round.

After her US Open success last September, the newest member of the Grand Slam champions club traded breaks freely with Schmiedlova after her opening service game and came up with a late hold to wrap up the first set.

Gauff, 19, stepped up a gear in the next set, as Schmiedlova continued to struggle on serve, and raced ahead 3-0 with a superb crosscourt winner from the deep to draw loud cheers from fans on Rod Laver Arena.

Coco Gauff in action at Melbourne.
Coco Gauff in action at Melbourne. Photo credit: Getty Images

Gauff was barely troubled from there, as she served out the match, finishing it off with a neat backhand winner to set up a meeting with fellow American Caroline Dolehide in the next round.

ASB Classic men's champion Alejandro Tabilo of Chile was due to face American Aleksandar Kovacevic in his opening match on Monday afternoon.

Meanwhile, Wimbledon champion Marketa Vondrousova has crashed to a stunning defeat in the opening round, as Ukrainian qualifier Dayana Yastremska outclassed her 6-1 6-2.

Seventh seed Vondrousova, who arrived in Melbourne after a hip issue forced her to withdraw from the Adelaide warm-up tournament, quickly found herself 5-0 down in the opening set, as Yastremska sensed an opportunity for a big upset.

The Czech, who became the first unseeded woman to claim the All England title last year, got on the scoreboard late in the first set, but the powerful Yastremska, 23, had built up far too much momentum and wrapped it up in style.

World No. 93 Yastremska, who reached the third round at Melbourne Park in 2019, secured the early break in the second set, as her opponent continued to spray the errors, and held firm to seal the victory.