Coco Gauff of the U.S. in action during her first round match [Source: Reuters]

U.S. Open champion Coco Gauff romped into the second round of the Australian Open but Wimbledon title-holder Marketa Vondrousova made a humbling exit at the hands of qualifier Dayana Yastremska.

Fourth seed Gauff admitted to making a nervous start in the first match on Rod Laver Arena but soon hit her stride to rattle off the last nine games for a convincing 6-3 6-0 win over Anna Schmiedlova.

Vondrousova was the first unseeded player to win the women’s title at Wimbledon last year but found the shoe on the other foot on Monday as she succumbed to a 6-1 6-2 upset loss at the hands of Yastremska.

The 2024 crop of qualifiers have caused a host of problems for top players on the first two days of the tournament, not least Dino Prizmic’s defiance of 10-times champion Novak Djokovic over four hours on Sunday night.

Men’s third seed Daniil Medvedev, who decided to skip the warm-up events this year, was perhaps fortunate that this opponent Terence Atmane retired due to cramp during his opening match on a sunbathed Margaret Court Arena.

The French world number 144, who had taken the first set off the 2021 U.S. Open champion before Medvedev levelled up the contest at 1-1, was holding his own in the third when he started suffering severe cramps in his thigh.

Atmane received a time penalty as he struggled get to the service line and another violation for smashing his racket in frustration but played on and even broke Medvedev’s service after a courtside massage.

The 22-year-old finally called time on his first Grand Slam main draw match while trailing the Russian 5-7 6-2 6-4 1-0.

There were emotional scenes on Court 13 where Italian qualifier Flavio Cobolli won his first Grand Slam main draw match with a 6-4 3-6 6-3 2-6 7-5 upset of Chilean 18th seed Nicolas Jarry.

Sebastian Korda, the 29th seed, needed five sets to get past Czech qualifier Vit Kopriva 6-1 6-4 2-6 4-6 6-2, while French lucky loser Hugo Gaston ousted Spain’s Roberto Carballes Baena 6-3 6-2 3-6 6-4.

In the women’s draw, Australian qualifier Storm Hunter beat former French Open finalist Sara Errani 6-4 6-3 to claim her first victory in the Melbourne Park main draw at the sixth attempt.

In an all-Australian tie on John Cain Arena, Alexei Popyrin beat Marc Polmans 6-3 7-6(3) 6-2 to set up a second-round clash with Djokovic.

There was no hint of an upset in the first match on 1573 Arena as Elina Svitolina, one of the band of mothers playing at this year’s tournament, beat local wildcard Taylah Preston 6-2 6-2.

Another of the mothers, Naomi Osaka, plays her first Grand Slam match since the 2022 U.S. Open against Caroline Garcia in the final match of the day on Rod Laver Arena.