Unseeded Canadian Frank Dancevic upset top seeded Russian Dmitry Tursunov of Russia 3-6, 7-6, 6-2 in the quarter-finals on the Indianapolis Championships on Friday.
Dancevic lost to Tursunov in the 2007 final at Indianapolis and is looking for his first ATP title.
"It's nice to get a victory over him," said Dancevic, who had lost the previous three meetings to the 27th-ranked Russian.
"I'm glad I played a solid match."
Tursunov captured the first set but could not recover after losing the second set tie-break.
"I had chances...but I couldn't convert them" Tursunov said.
"He got lots of free points. He served well, I didn't."
Dancevic will meet third-seeded Sam Querrey of the United States in Saturday's semi-finals after the American beat seventh-seeded Marc Gicquel of France 6-4, 7-5.
"This is my third year of reaching the semi-finals I'm finally hoping to make the jump into the final," Querrey said.
American Robby Ginepri, who beat compatriot Alex Bogomolov Jr. 7-5, 6-1, will meet John Isner in the second semi-final after Isner beat Wayne Odesnik 7-5, 6-7, 7-5.