A "pain-free" Novak Djokovic begins his Australian Open defence against a teenage qualifier on Sunday as he bids for an unprecedented 25th major crown, but women's top seed Iga Swiatek faces a much trickier assignment.
The opening Grand Slam of the year gets under way as a 15-day event for the first time, aimed at cutting down on late-night finishes.
World number one Djokovic is an overwhelming favourite, with a sore wrist that cast a shadow over his build-up no longer troubling him.
He should have few problems progressing from his evening clash on Rod Laver Arena against 18-year-old Croat Dino Prizmic, who is making his main draw Slam debut.
"It's exciting to be a part of another Slam," said the 36-year-old Djokovic, who has not lost at the Australian Open since 2018.
"I'm just hoping I can start the season in a way that I have been starting my seasons, most of my seasons, throughout my career, with a win here in Australia, in Melbourne. My favourite place, no doubt."
The Serbian's first real test could come in the third round, with a potential blockbuster showdown against fellow veteran Andy Murray.
Scotland's Murray, a five-time Australian Open finalist, begins against Argentine 30th seed Tomas Martin Etcheverry.
Djokovic surged to the title last year with a three-set victory over this year's seventh seed Stefanos Tsitsipas, who faces a tough first-round test from former top 10 Italian Matteo Berrettini.
If the Serb wins again, he will pass Australian Margaret Court's all-time Slam record and join Court (Australian Open) and Rafael Nadal (French Open) as the only players ever to win 11 times at a single major.
Adding to the intrigue, the number one ranking is at stake, with Djokovic, Carlos Alcaraz and Daniil Medvedev all in contention.
Alcaraz, who beat Djokovic in the Wimbledon final last year, is a different player from the one who last graced the Australian hard courts as an 18-year-old ranked outside the top 30.
After missing last year's event with a hamstring injury, he is now a two-time major champion and world number two.
"I am looking at reaching the final and hopefully playing a final against him (Djokovic)," said the 20-year-old Spaniard, who will meet French veteran Richard Gasquet first.
Russia's Medvedev, a Melbourne finalist in 2021 and 2022, kicks off against qualifier Terence Atmane, vowing to turn over a new leaf and tone down the on-court tantrums.
"I want to change, I want to mature," he said.
Former champions Naomi Osaka and Caroline Wozniacki make their return to Grand Slam tennis after having babies, among a clutch of mothers in the women's draw.
But world number one and top seed Swiatek is clear favourite, having been a dominant force since Ashleigh Barty's surprise retirement after winning the 2022 tournament.
The Pole is on a 16-match win streak, gunning for a fifth Grand Slam title and first in Australia.
She opens with a rematch of the 2020 Roland Garros final against Sofia Kenin that earned her a first major title.
"I know she's been playing some solid tennis. It's not going to be easy. I'll just get prepared the same way as usual," said Swiatek of the American, now ranked 38.
Defending champion Aryna Sabalenka, who last year became the first woman since Serena Williams in 2016 to reach at least the semi-finals of all four Grand Slams, will be a huge threat.
She is gunning for a second title after beating Elena Rybakina in the 2023 final and faces German qualifier Ella Seidel in an evening match on centre court Sunday.
"I did really a great pre-season. We worked a lot. I felt like we improved a lot," she said after warming up by making the Brisbane International final, where she lost to Rybakina.
Third seed Rybakina faces a bumper showdown first against former world number one Karolina Pliskova, while Osaka has a daunting task after being pitted against French 16th-seed Caroline Garcia.
