Heather Watson was left to fly the flag for Great Britain in Osaka as Laura Robson crashed out of the HP Open at the quarter-final stage.
Watson, unseeded here, needed almost two hours on court to overcome France's Pauline Parmentier 7-5 6-3 and reach the last four.
The Guernsey player prevailed over Parmentier, who is ranked two places below her at 73rd in the world, in a scrappy contest that saw 12 breaks of serve in 21 games.
Eighth-seed Robson was less fortunate, losing out on a third-set tie-break to Kai-Chen Chang of Chinese Taipei.
Robson dropped her serve twice in the first set but recovered to take the second set and level the match with world No 134 Chang.
The deciding set was a closely-fought affair with neither player managing to fashion a single break point.
But the British No.1 faded in the tiebreak as Chang secured a 6-4 3-6 7-6 (7-4) victory and a place in the semi-finals.
Top seed Sam Stosur will provide Chang's semi-final opposition after cruising past American Jamie Hampton 6-2 6-4.