Rafael Nadal, Nick Kyrgios and Simona Halep ease into Australian Open second round

Alexander Zverev pledges to donate $10,000 from each match as well as his entire prize money if he wins the title

epa08146893 Nick Kyrgios of Australia celebrates after winning his first round match against Lorenzo Sonego of Italy at the Australian Open Grand Slam tennis tournament at Melbourne Arena in MelbourneShow more

Rafael Nadal turned on the style as he launched his bid for a record-equalling 20th Grand Slam title at the Australian Open on Tuesday, while former finalist Simona Halep survived a couple of tumbles and a sore wrist before surging into the second round.

Australia's Nick Kyrgios also cruised through his opening assignment, but fourth seed Daniil Medvedev had to fight his way past American Frances Tiafoe in four sets.

Nadal, one shy of Roger Federer's Grand Slam mark, dropped only five games to beat Bolivia's Hugo Dellien 6-2, 6-3, 6-0 in just over two hours at a sunny Rod Laver Arena.

"It was a positive start," said the reigning Roland Garros and US Open champion, wearing a bright pink singlet and matching trainers. "What you want in the first round is just to win, and it's better if it's in straight sets."

He joins Federer and defending champion Novak Djokovic in round two as the Big Three look to tighten a stranglehold that has brought them all but one of the last 14 Australian Open titles.

On a bumper day of 88 first-round matches, after rain wiped out half of Monday's schedule, former US Open champion Marin Cilic and Canadian Milos Raonic both moved safely through.

Italy's Fabio Fognini, two sets down against America's Reilly Opelka when their match was suspended on Monday, returned to win it in five after a stormy encounter when both players argued furiously with the umpire.

A new star emerged in 18-year-old Italian Jannik Sinner, last year's NextGen champion, who earned his first Grand Slam victory against Australia's Max Purcell.

Australia's Kyrgios, who has spearheaded fundraising efforts for the country's deadly bushfire disaster, kept his notorious temper in check despite being taken to two tie-breaks in a 6-2, 7-6, 7-6 win over Lorenzo Sonego of Italy.

"I feel super-comfortable, you guys are the best. I feel the support.... I am ready to go again," Kyrgios told the crowd.

Medvedev, the narrow loser to Nadal in September's US Open final, dropped the second set against Tiafoe before recovering to win 6-3, 4-6, 6-3, 6-2.

Austria's Dominic Thiem, who has reached the last two French Open finals, went through in straight sets against Adrian Mannarino, while 2014 champion Stan Wawrinka needed four to get past Damir Dzumhur.

Alexander Zverev vowed to donate his prize money to bushfire relief if he picks up the Australian Open's Aus$4.12 million ($2.83 million) winner's cheque after he swept into the second round Tuesday.

The German seventh seed eased past the 77th-ranked Italian Marco Cecchinato 6-4, 7-6, 6-3 on Margaret Court Arena.

"I will donate $10,000 for every match I win," Zverev said after his opening round victory. "I know I'm not the favourite, but if I win (the tournament) I will donate every cent to the bushfires."

In the women's event, Halep recovered from a poor start to beat the big-hitting American Jennifer Brady 7-6, 6-1 and launch her title bid.

The 2018 Roland Garros and 2019 Wimbledon champion faces British qualifier Harriet Dart next in Melbourne.

Halep, 28, had her serve broken in the first game by the 49th-ranked Brady and the 2018 runner-up, was uncharacteristically flustered, taking a couple of falls, tossing her racquet and complaining to her coach.

She appeared to hurt her right wrist in one fall in the first set, and had heavy strapped by a medic.

"A little bit sore but nothing dangerous at this moment," the former world No 1 said. "So I will see tomorrow morning after I wake up."

Second seed Karolina Pliskova got exactly what she needed in her 6-1, 7-5 victory over a determined Kristina Mladenovic on Rod Laver Arena to advance.

"I think it was quite good for first match," Pliskova, who reached last year's semi-finals, told reporters. "Of course the match was not easy. So I think, yeah, it was a good test for a first round."