In-form top seed Iga Swiatek ground past former Australian Open champion Sofia Kenin in straight sets Tuesday to open her campaign for a first title at Melbourne Park.

But it was not easy for the four-time Grand Slam winner, who eventually triumphed 7-6 (7/2), 6-2 after a 1 hour 51 minute slog in draining conditions on Rod Laver Arena.

It was a replay of thee 2020 French Open final that Polish star Swiatek won, and they had not met since.

"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."

Victory stretched the 22-year-old's unbeaten streak to 17 matches, the second longest of her career, after she finished 2023 by winning 11 straight in Beijing and Cancun, which took her back to world number one.

She then won five more matches at the United Cup at the start of the new season, meaning she was in imperious touch coming to Melbourne.

There will be no let-up for Swiatek, with a second-round clash against either 2016 Australian Open winner Angelique Kerber or 2022 Melbourne Park finalist Danielle Collins.

Swiatek opened with a serve to love against 2020 champion Kenin, who has slid down the rankings to 41. But the American woke up and broke before holding to surge 3-1 clear.

With her left thigh strapped, Kenin was returning well and her backhand on fire.

But she wobbled in the sixth game, with back-to-back double faults gifting Swiatek a break back for 3-3.

Undeterred, Kenin earned another break with a searing backhand to move 5-4 ahead only to falter again serving for the set.

It went to a tiebreak, where the top seed stepped up to get over the line after a marathon 68 minutes.

The second set was equally tight until game five, when Kenin slapped a forehand wide to hand Swiatek two break points and she converted when the American pounded a backhand long.

It was a killer blow, with Kenin having nothing left in the tank as the world number one sprinted to the finish line.