Coco Gauff cruises in Aussie opener; Marketa Vondrousova ousted

MELBOURNE, Australia -- With increased confidence in her serve thanks to some advice from former No. 1 Andy Roddick, Coco Gauff began her quest for back-to-back Grand Slam singles titles with a 6-3, 6-0 victory over Anna Karolina Schmiedlova of Slovakia at the Australian Open on Monday.

The 19-year-old American, who won her first major at the US Open in September, wrapped up the victory in exactly one hour.

"I was a little nervous the first set," fourth-seeded Gauff said. "I think I did well returning, then I found my serve toward the end [of the set]. When I was nervous at 3-3, I told myself: 'I feel good, I look good, so just have fun.' That was able to relax me a little bit."

Gauff dropped just one point on her serve in the second set and said that Roddick had recently given her some serving tips.

"It was really cool," she said. "He's a really chill guy. I met him before but never to that level. I went to Charlotte [North Carolina] for two days. It was a really good two days. I think that my serve has improved. He's probably one of the best servers in history."

Gauff will face fellow American player  Caroline Dolehide in the next round.

Earlier, there was a surprising defeat for Wimbledon champion Marketa Vondrousova of Czechia, as she was beaten 6-1, 6-2 by Dayana Yastremska of Ukraine.

Vondrousova, the No. 7 seed, missed the Adelaide tuneup event with a hip injury and struggled on serve throughout, hitting seven double faults as she was well-beaten by the world No. 93-ranked player.

"I didn't practice because I was injured," Vondrousova said. "I think that was the important thing. I lost myself at the beginning."

Yastremska, who had lost in the first round in her past seven Grand Slam appearances, had 26 winners.

During her on-court interview after the match, Yastremska acknowledged the ongoing war in Ukraine and how proud she is of the Ukrainian people. She was emotional in recounting how a rocket had struck her grandmother's house while she was playing in Brisbane earlier this month. 

"I think we just need to remember about it and give as much support to Ukraine," Yastremska said. "But I'm proud to be Ukrainian, and thank you everybody for your support."

In other early play, 19th-seeded Elina Svitolina of Ukraine advanced to the second round, beating Taylah Preston, a wild-card entry from Australia, 6-2, 6-2.

Four-time major winner Naomi Osaka will later make her much-anticipated comeback to Grand Slam tennis after the birth of her daughter. The Japanese player will take on Caroline Garcia of France in the first round in the last match at Rod Laver Arena.

The Associated Press and Reuters contributed to this report.