Luke Gale was the hero as Castleford Tigers held off a late fightback from St Helens to reach their first Grand Final.
Returning to the side just 16 days after having his appendix removed, the England scrum-half scored a try and kicked four goals to put his side into what appeared to be a winning 20-10 lead after 64 minutes.
However, in a dramatic finish to an outstanding semi-final, Saints roared back with three tries in the last 10 minutes to edge in front before Gale kept his nerve to kick a last-minute penalty to send the game into golden-point extra-time.
80: Gale kicks the penalty goal and we're going to golden point. Tigers 22-22 Saints pic.twitter.com/tKNHp3349N— Castleford Tigers (@CTRLFC) September 28, 2017
He then demonstrated more composure to land the winning drop goal that earned his side a 23-22 victory that set up a first all-Yorkshire final for 12 years.
Castleford, who will meet the winners of Friday's semi-final between Leeds Rhinos and Hull FC at Old Trafford on October 7, have become the seventh club to reach a Grand Final and will be favourites to become only the fifth team to win a title held by just four teams in the 21 years of Betfred Super League.
Zak Hardaker crossed inside the first minute and Gale converted before kicking a penalty to give Castleford an 8-0 lead.
The boys are celebrating here at the Jungle after that nail biter!! pic.twitter.com/jyunpRqab9— Castleford Tigers (@CTRLFC) September 28, 2017
But they trailed 10-8 at the break following tries from Regan Grace and Morgan Knowles, the latter's converted by Mark Percival.
Gale and Adam Milner scored in quick succession to give the Tigers a cushion, only for Saints to come roaring back through Tommy Makinson, Percival and Ryan Morgan before the dramatic finale.
On Gale, Castleford coach Daryl Powell said: "On Monday he was pretty sure, I just wanted to give him until Wednesday. He handled it pretty well.
Great gesture from the Tigers squad to give retiring Andy Lynch a guard of honour as he left tonight! pic.twitter.com/cihJf6DGHJ— Castleford Tigers (@CTRLFC) September 28, 2017
"It was a phenomenal effort to get himself on the field in such a short space of time, although he might have hurt himself being dived on at the end.
"He held his nerve with the penalty and that drop goal was world class. To get it over over the top of onrushing defenders was pretty special."
Powell added: "It was such a crazy game. It was obviously really tight all the way through but we got a 10-point cushion and that should have been enough.
"But we were a little bit soft on our tryline. There were some disappointing things in there but it was unbelievable at the end and to come out on top in extra time is massive for us."
St Helens coach Justin Holbrook said: "It's really hard to take. It can be a cruel game at times - and it cost us.
"It will take some getting over. I'm obviously really proud of our boys, how we kept fighting, especially to come back in the second half."