Top seed Tomas Berdych and number three Milos Raonic both battled through for three-set wins to set up a Sunday final at the Thailand Open.
Berdych struggled for nearly three hours before finally defeating Frenchman Gilles Simon 6-7 (5/7), 6-2, 7-5. Raonic put out defending champion Richard Gasquet in the second loss of the day for France, 3-6, 7-5, 6-4.
The Canadian winner hammered 23 aces in a fightback lasting for just under two hours.
Czech Berdych had his troubles with the game of the 14th-ranked Simon, 2012 losing finalist.
Berdych is looking for his first title since Stockholm last October -- he is currently the lone member of the ATP top 10 without a trophy this season. Raonic owns four career trophies - three of them won indoors in the now defunct San Jose event.
Berdych beat Raonic in their only previous meeting.
Berdych lost the opening set after 74 minutes against Simon, known for long matches and extended passages of play.
After being treated on court for back pain on Friday, Simon did not use his courtside chair during changeovers in the Berdych match.
"It was a very tough match and very tight at the end," said Simon, the 2009 champion. "I played well in the beginning and then Thomas was very strong coming back in the second set and ultimately was too good in the end."
Berdych squared the match at a set each but had to keep up the pressure in the third before finally getting past the Frenchman who beat Jo-Wilfried Tsonga late week for the Metz title.
Berdych ended with 18 aces and six breaks of serve, saving 11 of the 14 break points he faced and coming from 0-40 down as he served for victory.
"I was a bit unlucky in the first set," said Berdych, winner of his third match from eight played against Simon. "I stuck to my tactics, which had been successful.
"I just tried to keep going in the same way, used the same strategy - it was a good option in the end.
"With Gilles you always expect a long match, that is his game. He likes long rallies. I tried to deal with that," Berdych said. "In the end it was very close but finally my serve helped me out and I was able to finish the win."
The Czech, playing in his seventh semi-final of the year and third in Bangkok after 2007-08, had lost his past three meetings against Simon.
Raonic made a strong recovery after being out-played by Gasquet in the first set.
"There are things I must do better for sure," said the world number 11. "I competed well but he played better and had more opportunities."
Gasquet had defeated Raonic in five sets at the US Open fourth round as Raonic fired 39 aces in the loss.
Raonic is into his third final of the season and his ninth overall.
