Naomi Osaka’s winning run came to an end as she fell to former world number one Karolina Pliskova in the final of the Pan Pacific Open in Tokyo.

The newly-crowned US Open champion, who was bidding to become the first Japanese winner of the event since 1995, succumbed 6-4 6-4 in a battle of two big servers.

It ended Osaka’s 10-match winning streak and handed Pliskova – currently ranked eighth, one place below Osaka – the 11th major tour title of her career.

Naomi OsakaNaomi Osaka was defeated in the Pan Pacific Open final in Tokyo (Eugene Hoshiko/AP)

Osaka served notice of her intentions as she started the match with a huge ace – but a netted backhand in her third service game handed Pliskova the crucial break in what would prove to be the only break point of the first set.

The second set continued in the same direction with both servers on top until Pliskova pounced in game nine, breaking her opponent to love and giving her the chance to serve out for the title.

Fittingly, Pliskova wrapped up the match in the same way Osaka had started it – with an ace – to take victory.

Kiki Bertens fought back from a break down in the deciding set to beat Ajla Tomljanovic and claim her third title of the year at the Korea Open in Seoul.

The Dutch second seed rallied after losing the opening two games of the decisive set, eventually winning 7-6 (2) 4-6 6-2 in two hours and 22 minutes.

It continued a best-ever season for Bertens, who added the Korea title to her previous triumphs in Charleston and Cincinnati.

Both players struggled to impose themselves in the opening set but it was Tomljanovic who appeared to grab the momentum in the second, breaking Bertens twice in succession to drag the match back level.

A superb start to the second set saw the Australian take control, and she held two points for a 3-0 lead before Bertens hit back, breaking her resistance and ultimately reeling off six successive games to claim her seventh career crown.