Serena Williams admits she might have been forced to skip the Australian Open if it hadn't been pushed back over the coronavirus, saying she needed extra time to shake off the Achilles tendon injury which cut short her 2020 season.

Williams, who beat Daria Gavrilova in her Yarra Valley Classic opener in Melbourne, suffered the injury at last year's US Open then withdrew from the French Open before the second round, ending her 2020 campaign.

But the 39-year-old American, who will launch her latest attempt for a record-equalling 24th Grand Slam title next week, got extra time to recover when the Australian Open was postponed for three weeks to implement international safety travel protocols for players arriving in the country.

"I couldn't practice because of my Achilles," she told reporters."I needed time. I don't think I would have been here if it was during the regular season.

"[The delay] was an unwanted blessing, I would say, but it was much needed for me.

"Achilles are like the worst thing, honestly. Oh my goodness, I didn't realise it would be this long. I definitely was pushing the limits, but I'm here."

An aggressive Williams showed no outward sign of injury as she beat home hope Gavrilova 6-1, 6-4 in the build-up tournament Monday.

The seven-time Australian Open champion started sluggishly, losing the first three points on serve, before quickly overpowering the Australian.

Gavrilova, ranked 451, was overmatched against her idol but used her speed around the court to make Williams work harder in a more competitive second set.

The American, though, had all the answers and it was a sharp performance from Williams, who lifted the intensity in her second match back after defeating world No 3 Naomi Osaka in an exhibition in Adelaide on Friday.

Williams, looking to get matches under her belt before the Australian Open, will next play Tsvetana Pironkova of Bulgaria in the round of 16.

In the night match, world No 2 Simona Halep wore down Anastasia Potapova from Russia with a 6-4, 6-4 victory in the Gippsland Trophy.

The two-time Grand Slam champion was pushed but claimed her second straight scalp having beaten top-ranked Ashleigh Barty in Adelaide.

"I knew it was going to be a difficult match because she hits very strongly and I'm happy to get through," she said.

Halep next plays the winner of Australia's Destanee Aiava and Laura Siegemund of Germany.

Earlier, teenage sensation Coco Gauff showed only glimpses of the form that fuelled her dazzling run at last year's Australian Open during a gruelling three-sets victory over Jil Teichmann at the Gippsland Trophy.

The 16-year-old overcame a mid-match stutter to win 6-3, 6-7, 7-6 in two hours and 45 minutes.

"All the training I did in the off-season meant I was able to go through three tough sets and not get tired," she said.

The American was one of the stories of Melbourne last year, where she upset reigning champion Osaka in straight sets in the third round.

World No 5 Elina Svitolina also moved through with a comfortable 6-1, 6-4 victory over former top-10 player Andrea Petkovic of Germany.

The 26-year-old Ukrainian, who has never reached the final of a Grand Slam, played her first match in Melbourne since emerging from the 14-day mandatory quarantine.

She fell in the quarter-finals to Russia's Veronika Kudermetova in Abu Dhabi last month.

"I think a few matches in Abu Dhabi helped me get straight into the match, and I started strong," she said.

The two WTA events are being played concurrently at Melbourne Park as players prepare for the Australian Open starting on February 8.