The 43-year-old Dubliner recovered from 9-4 behind and then 9-7 and 55-0 adrift to level his tussle with Matthew Selt at 9-9, forcing a deciding frame.
But that was where 1997 champion Doherty’s fightback ended, with Selt turning the screw to seal a 10-9 victory and a debut at the World Championships next Saturday.
Selt, 28, knew defeat would have been hard to take, saying: “It would have been catastrophic. Ken started playing well.
“I started to get a little edgy. But I knew if it went to a decider I would be calm because the pressure would reverse. I felt calmer (then) than when I was 9-4. Now it feels very, very good. I’m really looking forward to it. It’s massive for me.”