A last gasp Nick Haughton strike crushed Bamber Bridge hearts and booked Chorley’s place in the semi-final of the Lancashire FA Trophy.
Goals from both sides in a minute saw Chorley level through Matt Hughes after Alistair Waddecar had put Brig into the lead.
Brad Carsley was shown a straight red card early in the second-half, but the hosts battled and created chances for the remainder of the half.
However it was Matt Jansen’s men who struck the killer blow with penalties minutes away, Haughton volleying home an injury time winner.
The game started in a scrappy fashion, with both sides remaining solid at the back – the first sight on goal fell to Carsley, who fired a shot from the right wide of the mark.
Chorley’s star man Nick Haughton was beginning to see a lot of the ball and he went close on 18-minutes, drilling his shot inches wide of Lloyd Rigby’s right-hand post.
Brig started to gain a foothold just shy of the half-hour mark.
A superb piece of skill and then pass from Michael Potts saw Carsley almost find himself one on one, but a last-ditch tackle took the ball away from him.
A half of few chances then came to life, with two goals in a minute.
Chorley failed to clear the ball, which found its way to Waddecar inside the box, who slammed home the opener on the volley to give Neil Reynolds’ side the lead.
The saying you are most vulnerable when you have just scored could not have then been more appropriate, and within a minute the Magpies were level.
Waqas Azam delivered a deep cross from the right, Adam Roscoe nodded the ball down across goal to Matt Hughes who arrived in the box to rattle home the equaliser.
The hosts ended the half the stronger of the two sides.
Waddecar struck a well hit free-kick into the grateful arms of Matty Urwin, before the ball broke kindly for Carsley who saw his shot well blocked from close range.
Just shy of the half-time whistle Mooney looked destined to send Brig in ahead.
The winger found himself one on one up against Will Beesley, the Brig No.7 twisted and turned the centre-half, but his shot was deflected agonisingly wide of the post.
The first opportunity of the second half fell to goal scorer Hughes, who latched on to a flick on but could only blaze his volley over the bar.
On the 50th minute Brig were reduced to ten-men.
Carsley chased a ball over the top, Urwin hesitated, the Brig striker lunged in and was dismissed for a late challenge on the Chorley shot-stopper.
Despite being reduced to ten men, Brig carried on in pursuit of a second-goal and Mooney went inches away from scoring.
His left-footed curling effort was heading for the bottom left corner, but Urwin dived magnificently to tip the shot around the corner.
Jamie Milligan then replaced Matthew Mahoney for the hosts.
Moments later Potts dispossessed the visitors and slid the ball across for the onrushing Mooney, his side footed strike was well palmed away by Urwin however.
Jansen made a double change on the hour mark, Declan Evans and Jason Walker came on in place of Kieran Charnock and Dale Whitham.
Minutes after coming on, Walker could and probably should have fired Chorley ahead.
The ball fell to him after ricocheting off Milligan, and his strike on the half-volley flew inches wide.
It was then Danny Forbes who had a glorious chance to head Reynolds’ side ahead, but his diving header from a matter of yards out was off-target after the midfielder latched onto Milligan’s delivery.
The midfielder then went desperately close himself, clipping the crossbar with a wonderfully struck free-kick from the edge of the box.
Haughton had a half chance to win it for Chorley deep into normal time.
The No.7 found Carver inside the box with a neat pass, but the midfielder sliced his shot wayward after a one-two with the striker.
With penalties looming as the game went into injury time, Haughton landed the sucker punch to break Brig hearts with a goal late in the day.
Brig had defended admirably, but Haughton showed his class to pluck the ball out of the sky from the cross and rattle home an injury time winner for the Magpies.
A succession of corners handed Reynolds’ side some hope of levelling in the dying seconds.
Forbes’ looping header proved to be the last piece of action, as the full-time whistle sounded to send Chorley through to the semi-finals of the competition.