In front of a boisterous home crowd at the partially renovated stadium, Exeter took the lead through Jayden Stockley, whose clinical 27th-minute finish broke the deadlock after the first leg had finished 0-0.
A piece of individual brilliance from Hiram Boateng doubled the lead just after halftime, the 22 year-old midfielder using his strength to hold off a defender before embarking on a powerful run through the middle of the pitch, beating another defender then smashing his shot into the far corner of the goal.
An equally spectacular finish from Ryan Harley just past the hour mark effectively ended the contest. Receiving the ball in space from a throw-in, the former Brighton and Swansea midfielder turned and rifled a stinging, rising shot from well outside the area that left 'keeper Ryan Allsop with little time or opportunity to save it.
Nine minutes later, Matthew Green scored what would prove to be a late consolation for the Red Imps, latching onto a clever through-ball, but it proved too little too late as The Grecians secured a spot in the final against either Notts County or Coventry City on 28 May (AEST).