That's all from us! Thanks for joining us today for a packed day of action in Australia.

Same again tomorrow? Yes please.

See you then!

Last year's Wimbledon finalists take to the Melbourne courts on Monday. SW19 champion Marketa Vondrousova plays Ukrainian qualifier Dayana Yastremska on John Cain Arena and two-time Wimbledon runner-up, Ons Jabeur, also plays an Ukrainian qualifier, Yuliia Starodubtseva. That's third on Margaret Court Arena.

Two-time quarterfinalist Elina Svitolina faces Australian wildcard Taylah Preston first on 1573 Arena and 10th seed Beatriz Haddad Maia finishes play on Kia Arena up against 18-year-old Linda Fruhvirtova.

There's an eye-catching clash last on court six where American Taylor Townsend takes on the returning Spaniard Paula Badosa. Russian 16-year-old Mirra Andreeva makes her Australian Open debut as she takes on American Bernarda Pera on court 12.

We'll be back bright and early tomorrow with commentary on BBC Radio 5 Live beginning at 06:00 GMT for Andy Murray's opening-round match against Argentina's Tomas Etcheverry.

It has been a rocky six months or so for the former British number one and speaking to BBC Sport two weeks ago in Brisbane, Murray accepted this year could be his final one on the tour if it proved to be as challenging as the end to last season.

However, he thought practice sessions had showed his level "was good enough" to make encouraging progress in Melbourne and beyond. For how long he does not yet know.

Third seed Daniil Medvedev starts play on Margaret Court Arena against French qualifier Terence Atmane.

Former finalist Dominic Thiem ends play on the same court against 27th seed Felix Auger-Aliassime.

Stan Wawrinka, 2014 champion, takes on 20th seed Adrian Mannarino and US Open semi-finalist Ben Shelton faces Spaniard Roberto Bautista Agut.

Fan-favourite Gael Monfils is also in action on court six against German Yannick Hanfmann.

On Day Two of the Australian Open, US Open champion Coco Gauff opens Rod Laver Arena against Slovakian Anna Karolina Schmiedlova.

Last year's finalist Stefanos Tsitsipas then takes on lucky loser Zizou Bergs after Matteo Berrettini withdrew with a right foot injury.

Home favourite Alex de Minaur kicks off the night session against 2016 semi-finalist Milos Raonic.

Returning two-time Australian Open champion Naomi Osaka rounds out the order of play with her first round match against 16th seed Caroline Garcia.

Image source, Getty Images

And as we've just seen, Aryna Sabalenka made the perfect start to her Australian Open title defence.

The world number two overpowered the 18-year-old qualifier 6-0 6-1 in a ruthless 53 minutes on Sunday.

Greek eighth seed Maria Sakkari earned a 6-4 6-1 victory over Japan's Nao Hibino to secure her first Grand Slam win in a year.

Danish wildcard and 2018 Australian Open winner Caroline Wozniacki advanced to the second round after Polish 20th seed Magda Linette retired with injury.

And American Amanda Anisimova earned an impressive 6-3 6-4 win over 13th seed Liudmila Samsonova in her first Grand Slam since taking a seven-month break for her mental health.

Read more from the women's tournament here.

British number two Jodie Burrage says she needs to improve her self-belief after letting a one-set lead slip on her Australian Open main-draw debut earlier on Sunday.

Burrage, 24, was beaten 2-6 6-3 6-0 by Germany's Tamara Korpatsch.

"I've got to do some work and trying to back myself and believe a little bit more," said Burrage, who is ranked 102.

"You could see it today. It was just absolutely panic stations at some point."

Read more here.

Image source, Getty Images

Image source, Getty Images

Well that's all from the action in Melbourne on day one and what a cracker it's been.

Italian fourth seed Jannik Sinner made a promising start to his Australian Open title bid with a 6-4 7-5 6-3 win over Dutchman Botic van de Zandschulp.

Fifth seed Andrey Rublev survived a comeback from world number 78 Thiago Seyboth Wild to win a five-set thriller 7-5 6-4 3-6 4-6 7-6 (10-6).

There was bad news for former semi-finalist Matteo Berrettini as he withdrew before his first-round match against Stefanos Tsitsipas because of a foot injury

And in the evening session on Rod Laver world number one Novak Djokovic overcame 18-year-old Dino Prizmic 6-2 6-7 (5-7) 6-3 6-4 to get his title defence off to a winning start.

Read more about what happened in the men's tournament here.

Coco Vandeweghe
Former two-time Grand Slam semi-finalist on BBC Radio 5 Sports Extra

I wouldn't want to play on a Sunday. I think it's great for the fans to be able to come in on the weekend, to not take a day off work or find a babysitter for the kids. It makes it a tournament more for the fans.

What I don't like about it is potentially having two days off after a first round. That's something you don't want as a player. You want to go one right after the other.

A two-day rest is bit too much of a lull, especially early on in the season when you haven't played that many matches.

Image source, Getty Images

Aryna Sabalenka on returning to Rod Laver Arena where she won her first Grand Slam title last season:

"I'm super happy to be back in Melbourne. Last time I had incredible memories from here, unforgettable I would say. It feels so great to be back and feel the support, all the atmosphere. Thank you so much for staying this late and supporting. It's really important so thank you."

A perfect start for the defending champion.

That was the second quickest Australian Open match there has ever been in the main draw at just 53 minutes.

She'll have two days off now then next up it's another youngster in 16-year-old Czech player Brenda Fruhvirtova.

Coco Vandeweghe
Former two-time Grand Slam semi-finalist on BBC Radio 5 Sports Extra

I thought that was a great first round match from Aryna Sabalenka, coming out and doing what she's supposed to do as the number two seed.

She's supposed to win these matches with the authority.

Sabalenka fires down an ace and it looks like it might be just out but, fortunately for the Belarusian, it clips the outside of the line to hand Sabalenka another match point.

That one goes astray, too, though as she sends yet another effort long!

Image source, Getty Images

Sabalenka overcooks another one! Surely there aren't nerves creeping in now?

Deuce.

Image source, Reuters

Another match point passes Sabalenka by as she sends her backhand wide.

Third time lucky for the defending champion?

Three match points for Sabalenka. Seidel saves the first as the Belarusian double faults.

Seidel saves both match points as Sabalenka sends back-to-back shots long and the 18-year-old follows up with a powerful serve to take the hold.

The German breaks out in a huge smile as she takes her first game of the match and forces the second seed to serve for the match.

Seidel sends one long and that brings up two match points for the relentless Sabalenka.

The crowd cheer to encourage the youngster. They'd love her to take this game.

Coco Vandeweghe
Former two-time Grand Slam semi-finalist on BBC Radio 5 Sports Extra

Aryna Sabalenka is not letting Ella Seidel into any points, any long, extended rallies. That's what Sabalenka is supposed to do as the bigger hitter, as the person who's going to take the first punch.

You don't want to get into any extended rallies past four or five shots.