A smart finish from striker Kenneth Zohore and a late Jed Wallace penalty secured Millwall a deserved 2-0 victory at Preston.
The Lions were excellent value for their fourth success of the season to move them into the top six as they condemned Preston to another frustrating home Championship reverse.
The hosts have now lost all four of their league fixtures at Deepdale and failed to register a goal.
North End disappointed with the first opportunity of the game in the 11th minute.
Millwall defender Jake Cooper had clumsily fouled Emil Riis on the edge of his own box, only for Brad Potts to slam the resulting free-kick straight into the defensive wall.
The Lions meanwhile, with Shaun Williams, Kevin Nugent and Alex Pearce directing from pitch-side in the absence of Gary Rowett's isolating senior management team, responded with Mahlon Romeo heading on a pacey run before dragging a 20-yard strike just off target.
The visitors were beginning to get into their stride, and Zohore saw a shot deflected just wide after he had met a smart through-ball from Mason Bennett.
Bennett was again the architect minutes later, teeing up Wallace, only for the Lions' forward to fire a weak effort straight at grateful North End goalkeeper Declan Rudd.
With the London side looking resolute across the back, North End were finding it difficult to make any significant progress in their bid to try and arrest their dismal Deepdale form so far this season.
The hosts were thankful to Rudd in the 38th minute. The hugely impressive Ryan Woods played in Bennett smartly, and his curling 25-yard strike was superbly tipped over the crossbar by the flying North End keeper.
Millwall had definitely been the more enterprising of the two sides in the first half, but it remained goalless at the interval.
Preston had the first chance of the second period. Andrew Hughes leapt high to meet Ryan Ledson's corner, but headed into the side-netting.
Millwall then got the goal they had undoubtedly deserved nine minutes after the restart.
At the end of a neat move through the middle, Wallace squared a ball perfectly for West Brom loanee Zohore and he slotted his first Millwall goal past Rudd from six yards.
Now staring down the barrel at another potential home defeat, Alex Neil's side were probing but Millwall's defence was proving tough to breach.
They so nearly got through in the 69th minute. Daniel Johnson played a superbly-weighted pass into the path of sub Tom Barkhuizen, only for goalkeeper Bartosz Bialkowski to produce a brave stop from close range.
Millwall wrapped up their win with six minutes left when Jed Wallace slotted home from the spot after Barkhuizen had tripped defender Murray Wallace in the area.
