Alex De Minaur is ready to carry Australian hopes on his shoulders when he takes on Rafael Nadal in the third round in Melbourne.

The new kid on the block 12 months ago after a brilliant run to the final of the ATP Tour event in Sydney, the 19-year-old found himself going into his home Grand Slam this time as the Australian No.1.

He has already established a reputation as one of the fittest and fiercest competitors on tour and needed to show both those qualities in a five-set victory over Henri Laaksonen, quelling the Swiss qualifier's fightback to win 6-4, 6-2, 6-7 (7), 4-6, 6-3 after holding a match point in the third set.

De Minaur only arrived in Melbourne on Sunday after going one better and winning his maiden ATP title in Sydney, but he insisted he will be ready come Friday.

"The body's feeling good," he said. "I'm still young. I can't complain. I'm doing what I love. I'm going to have a nice relaxed day tomorrow. I'll be ready for my next round and really excited."

De Minaur will certainly need all his fighting spirit against the ultimate warrior in Nadal.

As the son of a Uruguayan father and Spanish mother who has spent much of his life in Spain, De Minaur grew up watching Nadal's remarkable feats.

The teenager said: "Rafa is pretty much like the king in Spain. He's done so many amazing things for the sport. He's had that many achievements. It's pretty incredible. It's going to be fun for me to get out on court and be able to test where I am.

"I think this is what you play for: to play the biggest guys and the best guys at the top of their level on the biggest stages."

De Minaur already has experience of playing Nadal, having met him at the same stage of Wimbledon, where he won only seven games.

"I've already stepped out on court and played him, so that whole experience of playing Rafa, that's not new to me any more," he said. "So hopefully this time around I can go a bit more relaxed, just focus on myself, try to play some good tennis."

Nadal looked sharper than he had in the first round in beating Australian Matt Ebden 6-3, 6-2, 6-2 to record his 57th Australian Open win, putting him third on the all-time men's list behind Roger Federer and Novak Djokovic.

He has been aware of De Minaur's potential for a while, saying: "Since a couple of years ago we know that we have a good player coming. I think he has improved a lot during the last three years.

"Today he is one of the best players of the world. That's the real thing. He's young, very young. He is winning a lot of matches. It's going to be a tough one."

Federer was given a good workout by Britain's Dan Evans before coming through 7-6 (5), 7-6 (3), 6-3 and next faces Taylor Fritz, who upset Gael Monfils 6-3, 6-7 (8), 7-6 (6), 7-6 (5).

Fritz was not the only young American to make waves at Melbourne Park on Wednesday, with 20-year-old Frances Tiafoe claiming the biggest scalp of the tournament so far with a 4-6, 6-4, 6-4, 7-5 victory over fifth seed and Wimbledon finalist Kevin Anderson.

Tiafoe, the son of immigrants from Sierra Leone, was introduced to tennis at a centre in Maryland where his father worked as the head of maintenance.

He is already in the top 40, and he said: "Those are the matches I feel like I'm dangerous. I'm starting to feel more comfortable finishing the match, not just playing a match. I'm definitely going to remember this one."

Roberto Bautista Agut continued to do things the hard way after his epic win over Andy Murray, again winning the first two sets before coming through in five against John Millman.

There were also wins for Marin Cilic, Stefanos Tsitsipas, Grigor Dimitrov, Tomas Berdych and Karen Khachanov.

In the women's singles, meanwhile, Caroline Wozniacki and Maria Sharapova set up a blockbuster third-round meeting.

Both women were in formidable form against Swedish opposition on Wednesday, with the defending champion beating Johanna Larsson 6-1, 6-3 before Sharapova dispatched Rebecca Peterson 6-2, 6-1.

After her 6-0, 6-0 rout of Harriet Dart in round one, the Russian has dropped the fewest games in the tournament.

She and Peterson did not arrive on Margaret Court Arena until after 11pm, and Sharapova said afterwards: "This is way past my bedtime. I was just thinking what time I'm going to get to sleep."

The Russian took the final two months of the 2018 season off and admitted after her victory over Dart that her troublesome shoulder continues to cause her pain.

Nearly two years into her comeback from a 15-month doping ban, Sharapova has not yet shown signs that she is about to return to the top of the game, but victory over Wozniacki on Friday would certainly be a statement.

The pair have met on 10 occasions before, although not since 2015, with Wozniacki leading 6-4.

Sharapova said: "I think her results, specifically in the past year, speak for her game, how she's been able to raise her level. I think the grand slam was the one trophy she was looking for. With determination she got there last year.

"She loves playing here, loves everything about this tournament. I certainly have a tough match ahead of me."

It was generally a good day for the leading names, with second seed Angelique Kerber, fifth seed Sloane Stephens, eighth seed Petra Kvitova and home hope Ashleigh Barty all winning comfortably.

There will be an exciting clash in round three between highly-fancied Aryna Sabalenka and 17-year-old American Amanda Anisimova, who reached the third round of a slam for the first time with a 6-0, 6-2 victory over 24th seed Lesia Tsurenko.

Ninth seed Kiki Bertens did fall, going down 3-6, 6-3, 6-3 to Anastasia Pavlyuchenkova, while Australian wild card Kimberly Birrell upset Donna Vekic.