Gary Wilson will face fellow Briton Martin O'Donnell in Sunday's Wales Open final after holding on to beat five-time champion John Higgins 6-4.
Wilson won a close match at Llandudno, scoring 147 and making breaks of 104, 82 and 89.
The Englishman led 5-1 until Higgins reeled out in three consecutive frames, but Wilson held on with a break of 73 to win.
In the first semi-final, O'Donnell posted a stunning break of 126 in the deciding frame against Elliott Slessor.
Higgins was aiming for his sixth Wales Open title, but Wilson got off to a strong start, opening with 104 points and leading 2-0 with 147 points.
Scottish Open champion Wilson took full control at 4-0, with Higgins recovering the frame with a break of 93.
Wilson replied to move within one frame of the final, but Higgins fought hard with breaks of 69, 66 and 78 to bring the score back to 5-4.
But Wilson kept his cool and held on for victory with a break of 73 on a night that made him the 199th biggest break in snooker history.
Wilson became the 13th player to reach that milestone and his fifth career-high.
“I'm very happy,” Wilson said. “I didn't do too many things wrong and played very well in the patches.
“147 was early in the match, I didn’t even think about it at first, I was just thinking about building a lead.
“It wasn’t until you were probably 40 or 50 that you thought, ‘The ball is here,’ and you could hear the crowd fanning you.
“We should have put it in the frame earlier. We had a chance.”
Higgins admitted he had no answer to Wilson's intense early form.
“For the first three and a half frames he was deadly…incredibly, two centuries in a row,” Higgins said.
“Gary played great. I give him credit… There was nothing I could have done.”
O'Donnell showed great composure and won his first semi-final by decision.
After a tense safety battle, O'Donnell took advantage of the opportunity and hit his first century in the game, winning 6-5 and reaching his first ranking final.
O'Donnell had built a 5-3 lead over his fellow Englishman, but Slessor made breaks of 95 and 65 to level the score.
“I was just having fun and remembering all the time you put in at the club and all the things you do,” O'Donnell said.
“I was like, 'Okay, let's see what you're capable of here, let's see if you're up to the task.'
“That was the only thing I was really focused on. Oddly enough, I probably felt the most calm in the five-a-side game.”
World No. 76 O'Donnell dominated world champion Luca Bressel in the quarterfinals, defeating Slesser, and Wilson won the 2022 and 2023 Scottish Open.
