Sakkari, who will face Russian Elina Avanesyan in the second round, endured a difficult 2023 with early exits at all four majors, her best result at a Grand Slam coming in Melbourne where she reached the third round.

But she managed to squash any nerves with a dominant performance against Hibino, cruising to victory without dropping a point on her first serve in the second set.

"You're always nervous, you want to perform well. When you're a top seed you're always going to play players who do well against you. It was a difficult match today emotionally but I'm happy I managed to do the job right and play a good second set," she said.

Sakkari has now won her first four matches of the year for the first time since 2021 after she secured three victories for her country at the United Cup.

Meanwhile, American Amanda Anisimova earned an impressive 6-3 6-4 win over 13th seed Liudmila Samsonova in her first Grand Slam since taking a seven-month break for her mental health.

The 2019 French Open semi-finalist said she felt "a lot more refreshed" and was now enjoying her tennis again.

France's Alize Cornet fell in the first round, losing 6-2 6-4 to qualifier Maria Timofeeva, while Czech ninth seed Barbora Krejcikova came from behind to beat Japan's Mai Hontama 2-6 6-4 6-3 and will next face Germany's Tamara Korpatsch, who knocked out Briton Jodie Burrage on day one.

The Australian Open has been extended to 15 days this year in an attempt to avoid late finishes - with this its first Sunday start.