World number one Ashleigh Barty returns ahead of Australian Open

A crowd of 4,000 people were at Memorial Drive, and Barty said: "I genuinely missed it so much and I cannot thank you guys enough for welcoming not only myself, but Sim, and all the other players here.

"I've been getting a little bit impatient the last two or three months getting ready to play, and I'm so excited to get started next week. It was the perfect preparation coming here."

The event marked the end of two weeks of quarantine for the players who travelled to Australia from abroad.

Six top players including Novak Djokovic, Rafael Nadal, Serena Williams and Naomi Osaka controversially completed their quarantine in Adelaide in what were seen as more favourable conditions than those experienced by their fellow professionals in Melbourne.

Nadal, who would move to the top of the all-time list of men's grand slam singles titles ahead of Roger Federer should he lift the Australian Open trophy later this month, looked sharp in beating US Open champion Dominic Thiem.

He said: "The last two weeks have been great. We can't thank enough South Australia and Tennis Australia for all the positive things they make.

"I hope to have the right preparation for the Australian Open. I won in 2009, but I think almost everybody forgot about that. I keep trying hard and this year is a special one and I'm going to keep trying my best."

Williams has been quarantining with her husband Alexis Ohanian and three-year-old daughter Olympia, and the family headed straight to the zoo after completing the 14 days.

The 23-time slam singles champion, who won a competitive encounter against Osaka, said: "We promised her we would take her to the zoo to see koalas and kangaroos.

"I'm so glad the quarantine is over because to be in a room with a three-year-old and being her best friend is definitely difficult, especially after training and working out. But it was fun. Honestly, I wouldn't trade anything for spending hours with her."

Djokovic caused a scare when he pulled out of his match against Italian teenager Jannik Sinner with blisters on his hand only to emerge on court and play the second set anyway.

The eight-time Australian Open champion said: "The emotion was strong in me to come out on the court today, seeing almost full stands. I just had to play."

In Melbourne, players began emerging from their quarantine periods, including some of the 72 players who had not been allowed out of their rooms for the full period following positive coronavirus tests for people on three of the charter flights.

Among those was Britain's Heather Watson, who was so keen to get on court that she headed to Melbourne Park after midnight for a hit on Rod Laver Arena.

Watson tweeted: "12:54am – FINALLY FREE from 15 days in strict quarantine and of course my first stop is Rod Laver Arena for a midnight practice!

"I don't feel like spending another night in a hotel room so I think I might just sleep here tonight."

The warm-up events ahead of the Australian Open, which begins on February 8, get under way on Sunday with two women's tournaments.

In the Gippsland Trophy, which features Halep and Osaka, British number one Johanna Konta has a first-round bye while Katie Boulter faces Anna Kalinskaya.

Qualifier Francesca Jones takes on 14th seed Nadia Podoroska in the Yarra Valley Classic, which is headlined by Barty, Williams and Australian Open champion Sofia Kenin.

Watson will have a few days to practise before competing in the Grampians Trophy, beginning on Wednesday.