Kei Nishikori is one win away from the title at the Swiss Indoors Basel after battling past Giles Muller in Saturday's semi-finals.
The Japanese star found himself seriously up against it, staring down two match points in the second set, but he rallied superbly to claim a 4-6, 7-6 (7-3), 6-3 victory and set up a final against Marin Cilic.
"Gilles is a great server and I wasn't making many returns today," Nishikori said. "I made a lot of unforced errors to lose the first set."
It looked to be business as usual for the World No 5 when he broke early for a 3-1 lead, but with Muller's groundstrokes gaining traction as the match wore on, Nishikori suddenly gave away two breaks in games eight and 10 to drop the first set.
There was no real comeback forthcoming in the second set, either, as Nishikori struggled to make any inroads on Muller's serve.
At 4-5, the Luxembourg veteran pounced and earned two break and match points but Nishikori dug deep and held serve before claiming the second set tie-break courtesy of a clever serve and volley.
The third set was as evenly contested as the first two, and it ultimately came down to a solitary break for the Japanese in the sixth game courtesy of a backhand pass.
"I knew he was coming in [on match point]," said Nishikori. "I tried to play with confidence even on my second serve. My arm was shaking a little bit, but I managed to get through that tough moment."
Awaiting Nishikori in the final is Croatia's Marin Cilic, who also had to fight back from a set down to defeat Mischa Zverev of Germany 4-6, 7-5, 6-3.