Rafael Nadal's victory march in the first round of the Australian Open was briefly held up on Monday when a ball boy took his racquet.

The bizarre incident happened between games in the first set, with the Spanish great leading 4-3 against Britain's Jack Draper at Rod Laver Arena.

"I need the racquet back," the 36-year-old defending champion, looking bewildered, told the chair umpire.

It was not immediately clear what happened, but it seems that Nadal asked for his racquet to be restrung, only for the ball boy to take the wrong one.

"The ball boy took my racquet!" a smiling Nadal shouted to Draper, explaining what the hold-up was.

It did not overly affect the 22-time Grand Slam champion as he went on to win the match, despite a second-set wobble, 7-5, 2-6, 6-4, 6-1.

"Not distracting, just a funny situation," Nadal told Eurosport later.

"I said 'I need the stringer', but I needed the stringer to look at the other racquets.

"So he picked up my racquet I was ready to play (with). But okay, he took it and no problem at all."

Azarenka turns 'obnoxious' soccer mom

Victoria Azarenka is known for her cool and composed demeanour on the tennis court, but the two-time Australian Open champion says she turns into a loud and obnoxious "soccer mom" on the sidelines of her son Leo's games.

A Paris St Germain fan since ex-England midfielder David Beckham briefly played for the French club a decade ago, Azarenka said her affiliation has rubbed off on six-year-old Leo, and both of them often wear matching PSG shirts.

"Leo is extremely into football now. I call it football, he calls it soccer - we have this debate," Azarenka told reporters after downing another former champion, American Sofia Kenin, in straight sets to move into the second round of this season's Grand Slam opener.

"He wants to play in Paris St Germain, that's his dream. I'm a soccer mom now and I love that. I'm obnoxious, like absolutely the most obnoxious.

"...It's a completely different emotion for me to support my son. I have no shame in screaming for him, like zero. But I'm very supportive. I want him to do well, I want him to achieve his dreams."

Azarenka, who won the Australian Open in 2012 and 2013, had a year-long maternity break in 2016-17, while a split with her partner and a custody battle over Leo was not settled until 2018.

Leo travels with Azarenka on Tour, and he stole the show in one post-match news conference in Melbourne last year when he sat on her lap and answered questions about her performance.

"It's been quite an experience for me just to go to his games, for example," Azarenka added.

"I actually even asked him, 'Leo, do you like when mommy supports you?' He goes, 'Yeah, I love it, mom'.

"'Am I not too loud?' He goes, 'Well, sometimes, but it's okay, I like it.' So it's a wholesome moment for me."

Tiafoe dazzles in colourful kit

Frances Tiafoe won his first-round match at the Australian Open on Monday but it was the American's outrageously colourful kit which set tongues wagging.

The world number 17 wore a matching vest and shorts that had squiggly haphazard lines of blue, purple, red, yellow and white.

Tiafoe's brazen outfit in his four-set win over Germany's Daniel Altmaier was the talk of social media.

"This outfit deserves to get to the second week minimum," wrote one Twitter user.

"Pink camouflage singlet? Only Tiafoe can rock this look," said another. Not everyone was impressed, however.

"You know Tiafoe is my guy," wrote one. "But that outfit."