Basel - Battling Kei Nishikori saved two match points to defeat Gilles Muller 4-6, 7-6 (7/3), 6-3 on Saturday for a place in the Swiss Indoors final.
Asia's top-ranked player performed his escape act in the second set against Luxembourg's big hitter, who rained down 20 aces in the two-and-a-quarter-hour thriller in Basel.
The Japanese, fifth in the world, will aim for only his second title of the season on Sunday against fourth seed Marin Cilic, who beat Germany's Mischa Zverev 4-6, 7-5, 6-3 in their semi-final clash.
Third-seeded Nishikori saved the first match point with a perfectly timed lob.
"I saw that he was almost touching the net, but my arm was shaking as it was match point," Nishikori said of the winner that pulled the score level late in the second set.
After his heroics in the second set, Nishikori was able to steady his game to earn a hard-earned win over Muller, ranked 37.
"I got more comfortable and played a good match. The balls fly a lot here, you really have to hit the ball," said a relieved Nishikori.
"Muller has a great serve. I'm just happy to have won the match."
Nishikori has already qualified for next month's ATP World Tour Finals in London for a third straight edition.
Results on the sixth day of the Swiss Indoors on Saturday in Basel (x denotes seeded player):
Kei Nishikori (JPN x3) bt Gilles Muller (LUX) 4-6, 7-6 (7/3), 6-3
Marin Cilic (CRO x4) bt Mischa Zverev (GER) 4-6, 7-5, 6-3