Neil Harris bagged a second-half brace as Millwall got back to winning ways with a convincing win at Play-Off rivals MK Dons.
Chopper put his penalty miss at Wycombe on Saturday well and truly behind him as The Lions produced the perfect response to their disappointing defeat at Adams Park.
Danny Schofield's stupendous 18th-minute strike handed Kenny Jackett's men a deserved lead, only for Aaron Wilbraham to level with the flukiest of deflected efforts on 52 minutes.
But Chopper was rewarded for his persistence and endeavour by first stabbing The Lions ahead in the 60th-minute before making the points safe with a clinical third six minutes from time.
The opening exchanges of Tuesday night's encounter were fairly scrappy and scruffy on a heavy pitch, but it was The Lions who spurned the first real opportunity of the game.
There were six minutes on the clock when Harris picked up a poor back header from Peter Levin. Former Den stopper Willy Gueret did well to smother the striker's effort with Steve Morison's follow-up shot deflected for a corner.
Chris Hackett then fizzed wide from long range as Kenny Jackett's men enjoyed a spell of sustained pressure.
That pressure and perseverence finally paid off after 18 minutes when the impressive Morison showed great awareness and an equally excellent touch to find Schofield in a central position.
Although he still had plenty to do took, the former Yeovil man took a couple of touches before producing a cracking finish from 20 yards for his sixth goal in a Millwall shirt.
The home side responded and there were a few anxious glances to referee Dean Whitehead when former Lions striker Jermaine Easter took a tumble in the area following a quick attack straight from the restart.
However the official waved away the home side's half-hearted appeals for a spot-kick.
Defender Darren Ward then showed his strength to hold off Easter as he threatened to burst through on goal.
Lions keeper David Forde was called into action with a great save to thwart Luke Chadwick's 23rd-minute goalbound effort as Paul Ince's side tried in vain to get back on level terms, but his charges were getting no change from a rock solid visiting rearguard.
In fact it was Millwall who were a whisker away from doubling their tally on the half-hour mark.
The tireless Morison was again involved, playing a neat ball to Liam Trotter. He in turn put Harris through on goal, but on this occasion the Lions top-scorer screwed his shot narrowly wide.
Millwall's chances continued to come thick and fast with Harris, Morison, Schofield and Alan Dunne all firing high, wide or too close to the target in quick succession.
Dunne was agonisingly close to heading The Lions into a 2-0 lead just before the break, only for his header from another pinpoint Hackett corner to flash past the post.
Millwall picked up where they left off and Schofield was denied his second goal of the game on 48 minutes when James Tunnicliffe somehow managed to block his goalbound strike.
Trotter (51mins) then tested Gueret in the home goal following a Hackett corner, but it was the home side who scored the most unlikely of equalisers seconds later.
To say that MK Dons conjured a goal out of nothing would be a massive understatement, with Wilbraham's shot appearing to take a double deflection before looping over the unfortunate head of Forde and into the roof of the net.
If MK's leveller was fortuitous, the goal that put Millwall back in front on the hour mark was as scruffy as scruffy can get as Harris prodded home at the second attempt from no more than a yard following an almighty scramble. They all count, and no-one amongst the vociferous 1,371 travelling Lions fans were complaining!
A great flowing five-man move came so close to producing a third goal as Jackett's men kept the pressure on, but on this occasion keeper Gueret stood his ground to prevent Schofield providing the perfect finish to a near-perfect move.
Harris whipped in a cross on 68 minutes that only needed the slightest of touches, sub Scott Barron curled over a couple of tantalising deliveries and a super cross from Tony Craig was crying out for a boot to connect with the ball as MK's one-paced defence were consistently stretched by the lively Lions.
Millwall made the game - and points - safe with six minutes remaining when Harris' produced a clinical finish from 10 yards that gave Gueret no chance.
It was certainly a sweet finish for his 16th goal of the season to open up a six-point gap on MK Dons, who are eighth in the table one place below The Lions.
More importantly, Millwall's sixth win in seven games keeps the pressure on the top six teams above as the business end of the season fast approaches.
MK Dons: Gueret, Lewington, McCracken, Easter, Wilbraham, Carrington, Woodarda (Stirling, 78mins), Tunnicliffe, Leven, Chadwick (Morgan, 74mins), Townsend. Subs not used: Gobern, Davis, Howell, Randall, Flanagan.
Scorer: Wilbraham (52mins)
Millwall: Forde, Dunne, Craig, Abdou, Robinson, Ward, Schofield (Fuseini, 90+3mins), Trotter, Harris (Obika, 90+1mins), Morison, Hackett (Barron, 74mins). Subs not used: Sullivan, Frampton, Grabban, Grimes.
Bookings: Robinson (52mins), Morison (90+3mins)
Scorers: Schofield (18mins), Harris (60, 84mins)
Ref: Dean Whitestone
Att: 10,610 (away 1,371)