Former world number one and new mother Naomi Osaka won her first match back after a long break Monday with a hard-fought victory over Germany's Tamara Korpatsch at the Brisbane International.

The 26-year-old was on court for an hour and 47 minutes before finally seeing off a gallant Korpatsch 6-3, 7-6 (11/9) on Pat Rafter Arena.

"I was super nervous, but I was excited to be out there," said Osaka, a four-time Grand Slam champion who stepped away from tennis in September 2022, citing mental health concerns.

After giving birth to a baby girl in July, she rediscovered her love of the game and decided to return for the 2024 season.

It looked like she had never been away when she broke Korpatsch to love in the opening game then broke once more to take the first set relatively comfortably.

But it was a different story in the second set as Korpatsch lifted and Osaka began to feel the pressure.

Korpatsch broke Osaka's serve to start the second set and although the Japanese star broke straight back, she was no longer as settled against the tenacious German.

Osaka did break once more and was serving for the match at 5-4, but she was broken again and it went to a tiebreak, where both players had their chances.

Osaka squandered two match points and Korpatsch two set points before Osaka prevailed on her third opportunity with a powerful forehand down the line.

She said courtside that motherhood had changed her outlook on the game, and she had felt too isolated from fans and fellow players previously.

"The last couple of years that I played before I had my daughter I didn't return as much love as I was given," she said.

"So I really feel like that's what I want to do in this chapter. I just really appreciate people coming out and cheering for me."