Tokyo - Top-seeded Juan Martin del Potro overcame Alexandr Dolgopolov of Ukraine 4-6, 6-4, 6-2 to reach the Japan Open semi-finals on Friday.
Del Potro took control when he broke Dolgopolov to go up 3-1 in the third set at Ariake Colosseum and then broke him again in the final game.
The Argentine will face sixth-seeded Nicolas Almagro of Spain in the semis on Saturday. Almagro beat local favourite and defending champion Kei Nishikori 7-6 (2), 5-7, 6-3.
Third-seeded Milos Raonic of Canada hit 11 aces in a 6-3, 6-3 quarter-final win over Lukas Lacko of Slovakia, lining up a semi with Ivan Dodig of Croatia.
"I got into the first service game right away and that allowed me to get into the match," Raonic said. "And I just got better and better."
Raonic is coming off a win in the Thailand Open last Sunday and will be seeking his third title of 2013. He lost in the final of last year's Japan Open to Nishikori.
Dodig beat Jarkko Nieminen of Finland 6-2, 7-6 (3).