Switzerland's Roger Federer hits a return against Steve Johnson of the US during their men's singles match on day one of the Australian Open tennis tournament in Melbourne on Jan 20, 2020. (WILLIAM WEST / AFP)

MELBOURNE - Despite billing itself as the summer Grand Slam, the Australian Open was brought to an abrupt halt by rain on day one of the tournament on Monday.

With Australia in the grips of a horror bushfire season and record breaking drought, the change of weather was not unwelcome, but did force the cancellation of a number of fixtures.

Matches on outside courts were suspended as rain hit Melbourne Park at about 3 p.m. local time, however the drawcard contests, hosted on the indoor stadium courts, continued.

Osaka said she hoped to remain focussed and not let the hype of playing for back to back titles get the better of her

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Among those progressing to round two were Roger Federer, Novak Djokovic, Naomi Osaka, Serena Williams, Stefanos Tsitsipas, Caroline Wozniacki and Australia's Ashleigh Barty.

Earlier in the day, reigning women's champion, Osaka beat Marie Bouzkova from the Czech Republic, 6-2, 6-4, kicking off her campaign for a second consecutive Australian Open title.

Osaka said she hoped to remain focussed and not let the hype of playing for back to back titles get the better of her.

"There's no… reward for being a defending champion and you just have to go into it with the mindset that everyone wants to beat you and it's going to probably be tougher the second time around," Osaka told reporters.

Osaka will be joined in the second round of the women's competition by two of the world's greatest, Williams and Wozniakcki, who also won their first round clashes.

Japan's Naomi Osaka (L) shakes hands with Czech Republic's Marie Bouzkova after victory during their women's singles match on day one of the Australian Open tennis tournament in Melbourne on Jan 20, 2020. (WILLIAM WEST / AFP)

Williams made short work of Russia's Anastasia Potapova, 6-0, 6-3, while Wozniacki - who is playing in her final tournament before retiring - beat Kristie Ahn from the US 6-1, 6-3.

Among the men's players moving through, veteran Federer topped Steve Johnson from the United States, 6-3, 6-2, 6-2, and Greece's Tsitsipas dispatched Salvatore Caruso, 6-0, 6-2, 6-3, despite a late flare from the Italian.

Seven-time Australian Open winner, Djokovic progressed with a harder fought victory against Germany's Jan-Lennard Struff, 7-6 (7-5), 6-2, 2-6, 6-1, on the main-stage, Rod Laver Arena.

"It's great to be back in this arena that has a very special place in my heart," Djokovic said in a post-match interview.

"This has been by far my most successful court in my career and I love coming back to Australia, the land of tennis."

Local hopeful and women's World No. 1, Barty had the home crowd on edge after losing the first set of her match, however she dominated the remainder of the contest against Ukraine's Lesia Tsurenko, for a final result of 5-7, 6-1, 6-1.

Australia's Ashleigh Barty hits a return against Ukraine's Lesia Tsurenko during their women's singles match on day one of the Australian Open tennis tournament in Melbourne on Jan 20, 2020. (WILLIAM WEST / AFP)

One of the day's surprises was the departure of the World 13th ranked Canadian, Denis Shapovalov who went down to Hungary's Martin Fucsovics, 6-3, 6-7, 6-1, 7-6.

The hot-headed Canadian youngster exchanged words with the umpire after receiving a code violation for slamming his racquet on the ground.

He claimed that there was no violation if the racquet did not break, however the umpire maintained that it was still an infringement.

"The rule (according to) what I know is that if I break my racquet, yeah you can code me," Shapovalov said in a post-match interview.

"But you can't code me for slamming it. I'm not doing anything and it didn't impact anyone and the racquet was still in tact."

China's women on song

Chinese players Zhu Lin, Zhang Shuai and Zheng Saisai all moved through to the second round after the first day of play, with Zhang staging an unlikely deja vu win over Sloane Stephens, 2-6, 7-5, 6-2.

China's Zheng Saisai hits a return against Anna Kalinskaya of Russia during their women's singles match on day one of the Australian Open tennis tournament in Melbourne on Jan 20, 2020. (JOHN DONEGAN / AFP)

Early in the match, Stephens looked primed to progress comfortably, but Zhang had other plans, remaining poised to force a tiebreak in the second set and dominate a decisive third.

The scoreline was eerily similar to the pair's match in the first round of the 2018 Australian Open, on the same court, with Zhang also triumphing after dropping the first set, 2-6, 7-6, 6-2.

In another three-set thriller, Zhu beat Viktorija Golubic from Switzerland 4-6, 6-1, 7-6 (10-5), showing her ability to turn the tide of a match and stay cool under pressure.

Having lost the first set, Zhu fought back hard, dominating the second and appearing to have established an unassailable lead over her opponent.

However, Golubic would not be easily beaten, forcing a third set tiebreak and requiring Zhu to muster an impressive level of composure to clinch the decider.

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Also moving through for China in less dramatic fashion was Zheng, who claimed her match against Russia's Anna Kalinskaya 6-3, 6-2.

Zheng will face defending Australian Open champion Naomi Osaka in round two on Wednesday.

Earlier, rain interrupted an exciting match-up between China's Yafan Wang and the United States' Alison Riske, with the American barely claiming a first set tiebreaker 7-6 (5), before the match was called off.