Millwall secured a priceless win on the road on Friday night as Jake Cooper's late goal secured a 1-0 win at local rivals Charlton Athletic in the Sky Bet Championship.
The big defender popped up with a rifled effort into the roof of the net nine minutes from time after Connor Mahoney's effort was parried by Dillon Phillips in the Charlton goal.
Millwall boss Gary Rowett opted to field three centre-halves in Shaun Hutchinson, Cooper, and Alex Pearce against The Addicks, with Matt Smith the lone striker.
Charlton had a pair of chances in the opening moments of the game, but Albie Morgan and Tomer Hemed were unable to convert.
From there, The Lions took control of the evening, with the duo of Jed Wallace and Smith integral - Jayson Molumby had Millwall's first effort of the night, but the former's crossing ability and the frontman's heading skills were put to the test multiple times from there.
Mahlon Romeo also lent his weight in the attempts to find the head of Smith as the half wore on, but despite numerous set-pieces and chances, the score remained goalless.
On 24 minutes, Hutchinson's pinpoint cross found the head of Smith, but Charlton stopper Phillips stretched to prevent the ball from nestling in the back of the net.
With 34 minutes on the clock came The Addicks' best effort, but fortunately, as Hemed broke free and advanced into the penalty area, Bartosz Bialkowski was there to pull off a solid save. Two minutes later, Ryan Woods' lofted ball found Jed Wallace, but Phillips saved well.
Hemed was once again at the forefront of Charlton's attacking play as he swivelled inside the area with just three minutes to play until the break, but he curled an effort wide of Bialkowski's far post.
Half-time substitute Ben Thompson was straight into action early in the second-half, squeezing a cross into the box which saw a Smith effort blocked, before Ryan Leonard's block stopped Josh Cullen's vicious volley on the penalty area from going anywhere near danger.
Charlton substitute Chuks Aneke then forced Bialkowski into a save at his near post, with both sub Tom Bradshaw and Romeo having attempts blocked before the latter skied an effort with 20 minutes remaining.
With nine minutes to go, however, The Lions took the lead - and it was a striker's finish from Cooper, as after Connor Mahoney's effort was parried by Phillips, the big defender was there to rifle the ball into the roof of the net.
A nervy last few minutes - and five in injury-time - followed, but The Lions held firm to claim all three points.
Charlton Athletic: Phillips, Matthews, Oshilaja (Doughty 75'), Lockyer, J. Pearce, McGeady (J. Williams 75'), Pratley (Sarr 90'), Bonne (Aneke 64'), Morgan (Field 46'), Cullen, Hemed. Subs not used: Amos, Purrington, Forster-Caskey, Green.
Booking: Oshilaja, J. Pearce, Lockyer
Millwall: Bialkowski, M. Wallace, Hutchinson, Cooper, J. Wallace (S. Williams 86'), Smith (Bradshaw 65'), Romeo (Mitchell 75'), A. Pearce, Molumby (Thompson 46'), Leonard (Mahoney 75'), Woods. Subs not used: Steele, Ferguson, Skalak, Burey.
Scorer: Cooper 81'
Booking: Molumby, Cooper, Mitchell
Referee: Dean Whitestone