Caroline Wozniacki has battled into the semi-finals of the Toray Pan Pacific Open in Tokyo with a straight-sets win over Carla Suarez Navarro.

The Dane, who finished runner-up in the US Open final last month, reached the final four in Japan 6-3 6-3, but it was not as straightforward as the scoreline would suggest.

Wozniacki lost her opening serve of the contest, but immediately broke back and managed to save three break points to give her a 2-1 edge in the opening set.

Neither player could hold their serve in the next five games, but Wozniacki earned enough break points to take a one-set lead in Japan.

It was a less hectic affair in the second set as games went by way of serve in the early stages, but Wozniacki struck to break Suarez Navarro's serve in the fifth game.

The Spaniard was able to grab a break of her own, but Wozniacki earned a double break to clinch the set and the match.