Rob Cross ended Michael van Gerwen's title defence in an Alexandra Palace classic to book a William Hill World Darts Championship final date with Phil Taylor.
The Englishman led for much of the semifinal and eventually finished off the defending champion in a sudden death leg to claim a remarkable 6-5 victory.
Cross, in his first season as a professional, is now on the verge of a maiden world title.
But Taylor is the man standing in his way after the 16-time champion ensured he would make his swansong in the New Year's Day showpiece with a 6-1 win over Jamie Lewis.
In a contest that finished after midnight, Van Gerwen was always chasing Cross as the players traded sets, until nudging ahead for the first time at 5-4.
Cross took advantage of uncharacteristically poor finishing from the Dutchman to set up a decider that followed the pattern of the match.
Both players squandered opportunities to win it before Cross held his nerve in sudden death.
Cross told Sky Sports Darts: "Words can't explain it. Don't get me wrong I played well, but the crowd helped me, they really did. They got on Michael's back and that's why I won.
"At points I felt inexperienced, I really did, but I still got through. I will come out (in the final) and want to win.
"He (Taylor) is my favourite player actually. He was dominant and now he's leaving, it's going to be special for him but at the same time I've got to do my own job and do what I need to do to win that game.
"I never expected this, it's amazing, absolutely amazing. I never expected this rise, I really didn't.
"I'm just a working boy, I come from a normal household and don't get me wrong, I believe in my own ability and that's only why I got here."