African star Ons Jabeur sees off Tamara Zidansek at Australian Open

The second seed, who has reached the final of the last two grand slams, struggled for form during the first two sets, saving three set points in the opener and then dropping serve twice in a row to lose the second.

But Zidansek's bathroom break allowed Jabeur to refocus and she finished strongly in a 7-6 (8) 4-6 6-1 victory.

"It was a tough match honestly," said the Tunisian. "Just not the way I wanted to play. But I kept fighting. Frustrating to lose the second set but I think I got the time to think and talk to myself more. The third set was really great."

Jabeur struggled with a back problem during the warm-up tournament in Adelaide and had strapping on her right knee here.

She said: "It's not a big injury but sometimes it might bother me. I try to take it one day at a time. I'm going to challenge myself and see if I cannot play 100 per cent."

Fourth seed Caroline Garcia had a much easier time of things against Canadian qualifier Katherine Sebov, winning 6-3 6-0, while fifth seed Aryna Sabalenka continued her good form by defeating Tereza Martincova 6-1 6-4.

Former finalist Garbine Muguruza had a poor season in 2022 and she fell in the first round, going down 3-6 7-6 (3) 6-1 against Belgian 26th seed Elise Mertens having served for the match in the second set.

Twelfth seed Belinda Bencic, who ended last season by leading Switzerland to the Billie Jean King Cup crown, eased to a 6-1 6-2 victory over Viktoriya Tomova.