Kieron Morris's two goals and a Louis Moult header saw Wrexham beat Torquay to reach their second FA Trophy final in three seasons.
The visitors, leading 2-1 from the first leg, survived a tense first half before Moult's header from a Dean Keates free-kick extended their lead.
Morris scored two goals in quick succession to seal victory for the 2013 winners.
Kevin Wilkin's side face North Ferriby United in the final on 29 March.
The Conference North side beat Bath City 4-2 on penalties in the other semi-final.
Wrexham manager Kevin Wilkin told BBC Radio Wales:
"I'm delighted for everybody concerned with the club - there was great support here and they got behind us.
"I thought we managed the game really well in the first half and we were terrific in the second half in front of goal and deserved the win.
"It's tough on Torquay to go out at such a late stage and I feel for them but I want to be selfish and I want our team in the final."