A penalty from Ryan Harpur sent Dungannon through to the BetMcLean League Cup final.
It needed extra time to separate the sides at Stangmore Park, where Harpur’s spot kick proved the difference.
A late strike from Swifts’ Peter McMahon cancelled out Colin Coates’ headed opener and meant another 30 minutes.
And it was Dungannon - and Harpur - who got the all-important second goal from the spot.
The Crues were first to threaten with Jordan Forsythe hooking an effort wide inside two minutes from a flick-on by namesake Owens.
Johnny Lafferty had the Swifts’ opening salvo, shooting over from Cormac Burke’s cross.
The first real chance fell to the North Belfast side after 27 minutes.
A corner caused all sorts of confusion and, after it was partially cleared, a thunderbolt from Paul Heatley cannoned off the crossbar.
Although Jordan Owens hammered the rebound home, it was from an offside position and rightly disallowed.
A neat turn and shot from Heatley was bravely blocked by Hegarty, before the Crues winger tested the goalkeeper with a shot from 22 yards.
The Swifts were appealing for a penalty towards the end of the first half after Harpur went down, but ref Andrew Davey didn’t give it.
Crusaders took the lead in the 49th minute.
A free-kick from Heatley found Coates, who met the cross with a glancing header, directing it into the net from close range.
The referee was in the thick of things with both sides having penalty shouts turned down.
Dungannon were appealing when Crues sub Craig McClean looked to handle inside the area, but nothing was given.
Another Crues sub Jamie Glackin, meanwhile, went down as the goalkeeper raced towards him, but again the ref was unmoved.
Ryan Mayse and David Armstrong had shots blocked as the Swifts looked to get back in the tie.
With 10 minutes remaining, Mayse cut inside and tried to cross to the back post. It only needed a touch - but the ball drifted behind.
However, the home side were coming more and more into the game, and they shocked Crusaders by levelling in the 85th minute!
McMahon, on in place of Alan Teggart, collected a midfield pass, ran through on goal and smashed the ball into the top corner.
And so to extra time, where Dungannon went in front in the 114th minute.
Lowe was fouled in the box, a penalty was given, and Harpur stepped up to fire home his kick and send the Swifts through.
DUNGANNON: Addis, Hegarty, Armstrong, McElroy, Harpur, Teggart (McMahon, 62), O’Rourke, Lowe, Burke (Fitzpatrick, 116), Hutchinson, Lafferty (Mayse, 20)
Subs not used: Coyle, Campbell
CRUSADERS: O’Neill, Burns, McCrystal (McClean, 49), Coates, Ward, Caddell, Forsythe, Lowry (Glackin 52), Snoddy, Heatley, Owens
Subs not used: Jensen, Bonner, Cushley
Referee: Andrew Davey (Bangor)