Iga Swiatek survived a tough test against former Australian Open champion Sofia Kenin to reach the second round in Melbourne on Tuesday as Carlos Alcaraz prepared to make his bow.
The Polish world number one came through 7-6 (7/2), 6-2 against the player she beat to win her first Grand Slam title, at the French Open in 2020.
In-form Swiatek, 22, twice came back from a break down in a gruelling first set lasting 68 minutes but stepped on the gas in the second set, winning the final five games to finish with a flourish.
The four-time major winner, now on a 17-match winning streak, will face either America's Danielle Collins or former winner Angelique Kerber next.
"Really happy, it's not easy to play the first match, especially the first Grand Slam of the season," said Swiatek, who owns three Roland Garros crowns and another at the US Open.
"Wasn't easy at the beginning to find my rhythm and I felt a little bit off and Sofia did everything to keep it that way.
"I'm happy that I managed to get through the second set."
There was also a first-round win for former US Open champion Sloane Stephens, who brushed aside Australian wildcard Olivia Gadecki 6-3, 6-1.
On the men's side, 11th seed Casper Ruud beat Albert Ramos-Vinolas 6-1, 6-3, 6-1, while Britain's Cameron Norrie, seeded 19th, saw off Peru's Juan Pablo Varillas in straight sets.
Another headline act of day three in Melbourne is Wimbledon champion Alcaraz, who is vying with Novak Djokovic for the coveted number one spot.
The Spaniard, 20, edged the Serbian great in a thrilling final at the All England Club last year to win his second major.
Since that meeting at Wimbledon, world number one Djokovic, a 10-time winner in Melbourne, has come out on top twice against his young opponent, including at the ATP Finals in November.
But Alcaraz, who missed last year's Australian Open with a hamstring injury, is undaunted as he prepares for his first match against veteran Frenchman Richard Gasquet.
He said the challenge of toppling Djokovic -- king of Rod Laver Arena -- gave him "extra motivation".
"I always want to play against the best players in the world to see what my level is," he said. "Obviously it's a good test, playing against him in the places or in the tournament that he's almost unbeaten.
"Yeah, I am looking to reach the final and hopefully playing a final against him. It would be great, obviously."
Last year's beaten women's finalist Elena Rybakina, fresh from winning the Brisbane International, takes on former world number one Karolina Pliskova.
Emma Raducanu, who faces America's Shelby Rogers, is an unknown quantity after an eight-month layoff.
The British player stunned the tennis world when she triumphed at Flushing Meadows in 2021 as a qualifier but only on one other occasion has she reached the fourth round of a Grand Slam.
However, she is confident she can recover her best form after a frustrating period.
"I think my level, to be honest, is just too good not to come through if I put consistent work together," she said.
