Naomi Osaka's first Tour-level final since 2022 ended early as the four-time major winner was forced to retire due to injury.

Naomi Osaka was left frustrated by injury as her first WTA Tour-level final in over two years ended early at the Auckland Open.

Osaka won the opening set 6-4 in Sunday's final, but was forced to retire hurt after taking a medical time out, handing the title to Clara Tauson.

It marked Tauson's first title since 2021, and her third overall.

"It’s not the way you want to win any match, and especially not the final," said Tauson, who was competing in her first final since 2021.

"I felt like I had some more tennis to show today."

Osaka, who will now aim to be fit for the start of the Australian Open – a tournament she has won twice – on January 12, had looked well placed to go on and claim her first crown since she triumphed at Melbourne Park in 2021.

The 27-year-old had broken Tauson twice on the way to a 5-1 lead, though the Dane had started to come back into it, clawing back a set point and reeling off three games in a row to get it back to 5-4, until a brutal forehand winner from Osaka closed out the set.

Ultimately, the discomfort got too much for Osaka, however, and after consulting with her trainer, she called time.