Barty has an immediate chance of a break here.

Rafael Nadal, the one member of the Big Three competing in Melbourne, began his bid for a 21st Grand Slam title in calm fashion.

The Spaniard is the only former Melbourne champion left in the men's draw and did not look troubled as he swept past America's Marcos Giron 6-1 6-4 6-2.

Elsewhere, Wimbledon finalist Matteo Berrettini overcame stomach problems to beat Brandon Nakashima.

The Italian said 'grazie' to Imodium after his 4-6 6-2 7-6 (7-5) 6-3 win.

Image source, Getty Images

A hold to 15 for Barty, who received a great reception from the home fans on her way to the court.

And here we go - Barty to serve and starts us off with a service winner, straight down the middle that Tsurenko can only get a weak backhand on to it.

Defending champion Naomi Osaka made a strong return to the Australian Open with a straightforward win.

Osaka needed just 70 minutes to see off Colombia's Camila Osorio 6-3 6-3.

There were also speedy victories for two-time champion Victoria Azarenka and French Open winner Barbora Krejcikova.

However, American teenager Coco Gauff is out after a 6-4 6-2 defeat by China's Qiang Wang.

We have live commentary on BBC Radio 5 Live Sports Extra so press the play button at the top of this page right now to listen along.

Ukraine's Lesia Tsurenko is ranked 120th in the world but she has been as high as 23rd.

This is the 10th time the 32-year-old has appeared in the Australian Open main draw, but she had to battle through three rounds of qualifying to do so, beating India's Ankita Raina, American Asia Muhammad and Russia's Elina Avanesyan.

Her best performance in Melbourne came in 2013 when she reached the third round before losing to Caroline Wozniacki.

But her longest run at a slam was in 2018 as she reached the quarter-finals of the US Open, defeating Wozniacki along the way, but lost to eventual champion Naomi Osaka in the last eight.

Ashleigh Barty has already picked up some silverware in Australia this year as she won the Adelaide International a week ago, but that wasn't enough for her as she added another trophy to that as well as her and Storm Sanders won the women's doubles.

Jonathan Overend
BBC Radio 5 Live commentator

If you look at the defeat last year to Karolina Muchova [in last year's quarter-final] - no-one really saw that coming.

She's not the sort of player who uses the home support feverishly to her advantage.

She's not the first player and she won't be the last to underachieve at her home slam, and if it doesn't happen for her, I won't be surprised.

Image source, Getty Images

World number one Ashleigh Barty is the women's singles' title favourite and also feeling refreshed after shutting her season down following the US Open.

With Australia’s strict quarantine restrictions making it impossible to find a window in which to head home during the 2021 season, Barty was on the road from early March until September.

She began her season in perfect fashion with a title in Adelaide last week, and said: “I’m excited to be back home in Australia, excited to be back playing.

“Obviously it was really nice to get a few matches in Adelaide and kind of roll on some momentum and know that I’m coming in here playing well. I’m just chomping at the bit to get after it.”

Barty is bidding to follow up her Wimbledon title last year by becoming Australia’s first home singles champion since Chris O’Neal in 1978.

“I just have to hope that everyone understands I’m giving it my best crack,” said the 25-year-old, who reached the semi-finals two years ago.

Welcome back, or if you have just got up, welcome along.

Not long before the evening session gets under way and Ashleigh Barty has a whole country behind her as she looks to become the first Australian to win here in more than 40 years.

We're going to take a short break.

Tennis Breakfast will be on air on 5 Live Sports Extra from 07:00 GMT - you can listen using the player at the top of this page.

We'll be back at 08:00, when world number one Ash Barty begins her bid for a home Grand Slam title.

See you then.

Defending champion Naomi Osaka breezed into the second round with a 6-3 6-3 victory over Camila Osorio in just 70 minutes.

There were also wins for Maria Sakkari, Belinda Bencic and Elina Svitolina on the opening day at Melbourne Park.

In the men's draw, Rafael Nadal eased past Marcos Giron as he seeks his first Aussie Open title since 2009.

Wimbledon finalist Matteo Berrettini and teenage sensation Carlos Alcaraz were also among the winners.

Tunisian ninth seed Ons Jabeur has withdrawn from the tournament before her first-round match against Nuria Parrizas Diaz.

Jabeur injured her lower back during the Sydney Classic last week.

"Unfortunately, the pain is still very present and playing in such conditions could jeopardise my whole season," she posted on Twitter a little earlier.

Image source, Getty Images

There's a match point for Nadal, as Giron finds himself unable to return the Spaniard's serve...

And Nadal casually rattles down an ace to save it.

Deuce.

Nadal pops away a winner for 30-30, but an unforced error from the Spaniard hands Marcos Giron a very welcome break point.

Meanwhile, Rafael Nadal is about to ease into the second round.

He's serving for the match against Marcos Giron after an hour and 44 minutes.

That was an absolute beatdown from Seb Korda on his Australian Open main draw debut.

He'll play either Lucas Pouille or Corentin Moutet next.