THE HAGUE, Netherlands (AFP) — Former world No. 1 Naomi Osaka was dumped out of the 's-Hertogenbosch grass court tournament in a deciding tie-break thriller Friday, ending an encouraging run on the surface ahead of Wimbledon.

A battling performance by Canadian Bianca Andreescu, ranked a lowly 228 in the world, took her into the semi-finals with a 6-4, 3-6, 7-6 (7-3) victory over the four-time Grand Slam champion.

Andreescu will next face Dalma Galfi from Hungary for a place in Sunday's final, with the draw opening up after the defeat of top seed Jessica Pegula.

"For me today it was just about trying my best to stay in the present moment. She has a great serve, my focus was just to get the ball back into the court on return," Andreescu said after the match.

"Staying mentally tough was key today."

Two lengthy rain breaks meant both players struggled for consistency early in the match, which went on serve until the seventh game when Andreescu seized the initiative.

A powerful return down the line and an Osaka error handed the Canadian a break, which she backed up with a love service game marked by a string of mistakes from the Japanese player.

Andreescu managed to serve out the first set 6-4 in 40 minutes, cleverly breaking up Osaka's rhythm with heavily sliced drop shots.

But the Japanese hit back instantly in the second set, breaking Andreescu's first service game with a sweet crosscourt forehand drive on break point and racing to a 3-0 lead.

An Andreescu double fault gifted her opponent the double break and Osaka closed out the second set 6-3 with a service winner.

The only previous match between the pair was a nail-biting three-setter in Beijing in 2019 and the third set was also closely fought.