The 50th edition of the Australian Open is under way with a late change in forecast providing relief for players and fans alike.

Temperatures were forecast to hit 34°C in Melbourne on Monday as  tens of thousands of supporters flocked to the Melbourne Park precinct for the first grand slam of 2019.

With a combined prize pool of $62.5 million, the world’s best players have all fronted up as Roger Federer and Caroline Wozniacki look to defend their singles crowns.

Both will be in action later on Monday, but it was Sweden’s Rebecca Peterson who was the first player to book her spot in the tournament’s second round.

Peterson beat Romanian Sorana Cirstea 6-4 6-1 on Court 15 and former World No.1 Maria Sharapova was not far behind, thrashing British qualifier Harriet Dart 6-0 6-0.

Maria Sharapova of Russia serves against Harriet Dart of Great Britain. Photo: Getty

Astra Sharma was the first Australian to win, the 23-year-old edging out countrywoman Priscilla Hon 7-5 4-6 6-1 and local Zoe Hives won as well, proving far too strong for American Bethanie Mattek-Sands 6-1 6-2.

The first upset of the grand slam also came in the women’s singles as American Danielle Collins came from behind to beat 14th seed Julia Goerges 2-6 7-6 (7-5) 6-4.

In the men’s singles, Australian wildcard James Duckworth showed some good signs before going down to Spaniard Rafael Nadal.

Nadal won 6-4 6-3 7-5 on Rod Laver Arena.

Australian Alex de Minaur – the top-ranked local male in the draw – is currently on court battling Portugal’s Pedro Sousa. De Minaur won the first set 6-4.

John Millman, Matthew Ebden and Jordan Thompson will all be in action.

Monday evening’s action on centre court will be preceded by a ceremony recognising 50 years of the Australian Open.

Rod Laver won the inaugural men’s singles edition of the tournament in the Open Era – first held in Brisbane in 1969 – and the Australian legend will be part of a special tribute that will also feature singer Russell Morris.

Defending champions Wozniacki and Federer will then begin their Open campaigns on Rod Laver Arena, taking on Alison Van Uytvanck and Denis Istomin respectively.

Ashleigh Barty will take on Luksika Kumkhum, while Bernard Tomic faces a tough test against Marin Cilic on Margaret Court Arena in the evening session.

Also on Monday evening, Murray will meet Spaniard Roberto Bautista Agut on Melbourne Arena.

Men’s draw – what to watch

While Federer is eyeing off a 21st grand slam singles title – which would be his seventh at Melbourne Park and his third in a row – he is likely to face stiff competition from World No.1 Novak Djokovic.

The top seed is in good form and has also won six Australian Open titles.

Andy Murray announced last week that he plans to retire after Wimbledon, but that the Australian Open could be his last hurrah as he struggles with a persistent hip injury.

Nadal is also overcoming injury problems while De Minaur, Australia’s best hope, comes into the event after winning the Sydney International.

“I’m ready to go … the body is feeling good. It [winning in Sydney] has given me a lot of confidence,” he said.

Mark Edmondson was the last Australian to win the men’s singles at the event – way back in 1976.

Women’s draw – what to watch

All eyes will be on Serena Williams, who begins her quest for an eighth Australian Open singles title on Tuesday.

Williams will equal Margaret Court’s record of 24 grand slam singles titles if she is successful in Melbourne.

Victory would give Williams her first grand slam singles success since giving birth last year.

Wozniacki, Simona Halep and even Barty are all considered good chances in Melbourne.

Barty, who is seeded 15th, has lost in the third round at the Open in 2017 and 2018.

But an appearance in the final of the Sydney International has filled the Queenslander with confidence.

“I’m a different player than I was 12 months ago. I feel like I’m a much better player. I’m a more complete player,” the 22-year-old said.

Like the men’s singles, it has been more than 40 years since an Australian won the women’s singles title at the Open.

Chris O’Neil was victorious in 1978.