Alexei Popyrin says there is no point playing unless you believe you can win, as he books a second-round showdown with Novak Djokovic.

Five-time finalist Andy Murray hints he may have played his last match at an Australian Open.

Meanwhile, Coco Gauff is channelling her hero as she begins her quest for more grand slam glory. 

Here are five quick hits from day two at Melbourne Park.

1. Alexei Popyrin backs himself against Novak Djokovic

Australian Alexei Popyrin has booked a second-round match with defending champion Novak Djokovic.

Popyrin defeated fellow countryman Marc Polmans in straight sets on Monday 6-3, 7-6 (7/3), 6-2, setting up a headline clash with the world number one.

Despite Djokovic being the overwhelming favourite, Popyrin was not afraid to talk himself up to media on Monday.

"I'm going in there with full confidence," he said.

"If I don't go in there with that confidence, there's no point going in there.

"So, for me it's no other match. It's just me playing the world number one. It's just another match for me."

Popyrin added: "I think there is no point going into the court if I don't believe that I can [win]."

Djokovic is a 10-time champion at Melbourne Park.

He has only failed to reach the fourth round in Melbourne three times, with 2017 being the last occasion that happened.

2. Andy Murray hints he may have played his last Australian Open

Andy Murray has hinted this may be his last Australian Open after making a first-round exit.

The former world number one, a five-time finalist at Melbourne Park, went down in straight sets to Argentina's 30th seed Tomás Martín Etcheverry, 6-4, 6-2, 6-2.

When speaking to the media after the match, Murray steered clear of giving a definitive answer when asked whether this was his farewell appearance at the Australian Open.

But he gave an indication he won't be returning to Melbourne as a player.

"It's a definite possibility that will be the last time I play here. I think probably because of how the match went and everything, I don't know," he said.

"Whilst you're playing the match, you're obviously trying to control your emotions, focus on the points and everything. When you're one point away from the end, you're like, 'I can't believe this is over so quickly.'

"In comparison to the matches that I played here last year, it's the complete opposite feeling walking off the court.

"I wish I involved the crowd more. I'm just disappointed with the way I played and all of that stuff, so [it's a] tough, tough way to finish."

Murray has been a finalist five times at Melbourne Park, but was never able to win the grand slam.

3. Feel good, look good, play good

Reigning US Open champion Coco Gauff has surprisingly never made it past the fourth round at the Australian Open.

But, based on her utter demolition of world number 67 Anna Karolina Schmiedlova, she has to be once again in the conversation for favourites on the women's side of the draw.

The fourth seed took just an hour to complete the 6-3, 6-0 drubbing, winning eight straight games to finish off the Slovakian without really breaking a sweat on Rod Laver Arena.

Gauff, who is still only 19 years old despite making her grand slam debut five years ago, was sporting an on-court look that drew immediate comparisons to her idol, Serena Williams.

And she shouted out the black and yellow fit after the match as helping her relax after a slightly nervous start to the match.

"I feel good, I look good, so just have fun," Gauff said.

"I needed to just be happy on court."

4. Medvedev makes it through as cramping qualifier reduced to tears

Reigning US Open champion and two-time Australian Open finalist Daniil Medvedev is among the favourites for the title once again this year, but his opening match against French qualifier Terence Atmane was a bizarre one.