Steve Morison's splendid 17th goal of the season strengthened Millwall's place in the League 1 Play-Offs as Neil Harris' men recorded a fifth succesive home win against struggling Fleetwood Town.
Morison's strike - a sublime 52nd-minute lob - was just rewards for a Lions side who showed great resilience to withstand a late onslaught from Steven Pressley's Cod Army and move up to fourth in the table.
Harris made two changes with injury and suspension robbing the manager of Shane Ferguson and Shaun Williams respectively. Top scorer Lee Gregory, who started Saturday's game on the bench, returned to partner Steve Morison up front whilst Jimmy Abdou replaced Williams, starting a three-game ban, in midfield.
There was also a first ever appearance on the bench for Czech Republic youth international Kris Twardek.
The Lions were looking for an immediate response to the weekend defeat at Coventry City, a result which enabled both Barnsley and Rochdale to close the gap in the race for a Play-Off spot.
And in the opening five minutes, the signs looked promising as Millwall enjoyed the majority of the early possession, with midfielder Ben Thompson spraying the ball to both the left and right flanks at regular intervals, looking to stretch the visitors' defence.
Gregory was a whisker away from connecting with Morison's searching cross, but unfortunately after a reasonable start, The Lions were increasingly pegged back and frustrated by a well organised Cod Army who could count themselves unlucky not to go in ahead at the break.
An almighty goalmouth scramble four minutes before half-time saw The Lions ride their luck because when the ball finally did fall to Robert Grant, his effort smacked the woodwork and the ball bounced clear.
The home fans breathed a collective sigh of relief in the final minute of the half when Jimmy Ryan's jinking run was brought to a halt by Mark Beevers' trailing leg, but referee Ross Joyce waved play on and The Lions lived to fight another day, or at least the second half, on level terms.
A change at the break saw Gregory replaced by youngster Jamie Philpot, and the sub's impact was immediate. Within seven minutes of the restart Philpot's neat flick picked out Morison in the 18-yard box and the skipper's finish was as cool as you like, nonchalantly lobbing Chris Maxwell in the Fleetwood goal.
Chris Taylor was inches away from doubling Millwall's tally six minutes later, heading narrowly wide from Morison's deep cross whilst at the other end a rasping, rising drive from Stefan Scougall flashed narrowly over the bar.
At this stage of the season it's about grinding out the results, and Harris' men did just that because for long spells after getting their noses in front, they were forced to repel wave after wave of attacks.
It was scrappy, there were plenty of desperate defensive clearances and nervy goalmouth scrambles that with every bobble of the ball had the home fans biting deeper into the quick of their finger nails.
But with goalkeeper Jordan Archer an unbeatable last line of defence - his double injury-time save to deny Wes Burns testament to that - this was all about getting those three points and Millwall did just that, edging ever closer to securing a top six finish with just three games left.
Archer, Romeo, Martin, Beevers, Webster, Abdou, Thompson, O'Brien (Upson, 88mins), Morison (Onyedinma, 70mins), Gregory (Philpot, 46mins), Taylor. Subs not used: Forde, Edwards, Craig, Twardek.
Romeo (30mins), Philpot (58mins)
Maxwell, McLaughlin, Jordan, Jonsson (Hunter, 80mins), Pond, Bell, Ryan, Burns, Grant (Cole, 72mins), Sarcevic, Scougall (Ball, 80mins). Subs not used: Gogic, Forbes, Nilsson, Grant.