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Italian Jannik Sinner ended 2023 in scintillating form and picked up where he left off. The fourth seed beat Dutchman Botic van de Zandschulp 6-4 7-5 6-3.

Marin Cilic, a runner-up in 2018, is out after losing 6-1 2-6 6-2 7-5 to Hungarian Fabian Marozsan on 1573 Arena.

Melbourne Park has also seen a couple of five-set matches.

Argentine Francisco Cerundolo held off Australian qualifier Dane Sweeny on John Cain Arena. The 22nd seed beat the home favourite 3-6 6-3 6-4 2-6 6-2.

Russian Kotov survived a comeback from Frenchman Arthur Rinderknech to win 7-5 6-1 6-7 (6-8) 6-7 (5-7) 6-3 on court 6.

Former semi-finalist Matteo Berrettini has withdrawn from his match against seventh seed Stefanos Tsitsipas because of a right foot injury. You can read more about that and the rest of the men's singles results here.

Lots has already happened on the opening day so far, so let's have a quick recap of what you may have missed if you're just waking up!

Jonathan Jurejko
BBC Sport in Melbourne

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Hello from Melbourne! Well, g'day.

While everyone back in Blighty shivers in the low temperatures, the nation's top tennis players have been warming up - literally and metaphorically - for a crack at the first Grand Slam prize of the 2024 season.

Seven British players started in the men's and women's singles draws, but that has already been reduced to six after Jodie Burrage lost earlier today.

Andy Murray is the next 'Pom', as they say round these parts, in action tomorrow.

Emma Raducanu, Katie Boulter, Cameron Norrie, Dan Evans and Jack Draper start their campaigns on Tuesday,

As well as the Brits, the usual star names - Novak Djokovic, Iga Swiatek, Carlos Alcaraz, Coco Gauff, etc - are all back in town.

If you've only just woken up to the fact the Australian Open is kicking off, don't worry.

Read up here on what are expected to the main storylines.

Hello, good morning and thanks very much for joining us so early on your Sunday morning for the start of the Australian Open!

While we build up to the first night session at Melbourne Park, we want to hear from you.

Who are you most looking forward to seeing in action, who are you expecting to star, and who do you expect to take home the titles?

Also, let us know how you're planning to deal with the late nights/early starts to follow your favourite players!

There are three ways to get in touch with us:

Use #bbctennis on X (formerly Twitter), text us on 81111 or send us a message via WhatsApp on 03301231826.

Remember to include your name and where you're from so we can feature you on the feed!

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Reigning singles champions Novak Djokovic and Aryna Sabalenka are the headline acts in the first night session at this year's Australian Open from 08:00 GMT.

Djokovic, who is aiming for a record-extending 11th men's singles title in Melbourne, faces Croatian teenager Dino Prizmic.

Then, Belarus' Sabalenka plays 18-year-old qualifier Ella Seidel of Germany.

Not a bad opening night at all.

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It's time.

The opening Grand Slam of the season is upon us, with the action at the 2024 Australian Open already well under way.

But there's plenty more to come, on this the-now 15-day tournament's first ever Sunday start.

And a whole lot to look forward to over the coming fortnight as the world's best battle it out to make a statement by landing the first major title of the year.

Welcome all!

Image source, Getty Images