NIGEL Clough named an unchanged side to the one that kept a clean sheet in the 0-0 draw last time out against Oldham Athletic.
The Brewers started the brightest of the two sides and forced some early chances. Beavon was brought down by Martin on the wing which Mousinho very nearly nodded home the resulting free kick, only for Webster to block and clear well.
Mark Duffy was then presented with a good opportunity inside the box as Tom Naylor Found Calum Butcher on the edge who fed the ball through to the Albion winger but his shot was too tame for Archer in the Millwall goal who got down to his left to palm the ball away.
GOAL: Against the run of play it was the home side that took the lead. Gregory chased a long ball down the right before cutting inside and laying it to O'Brien who made no mistake in pulling off a fine finish to beat McLaughlin in the top corner. 1-0
GOAL: The home side gained confidence from their first goal and they didn't waste time in adding a second. Just 6 minutes later Williams played a ball over the top for Gregory to chase which he did before rounding McLaughlin and slotting into an empty net. 2-0
The two quick-fire goals seemed to take the wind out of Albion's sails although Calum Butcher came close with a header from Damien McCrory's cross but Jordan Archer watched it wide to his left-hand post.
Chances were limited for the Brewers in the first half and Mark Duffy's early effort was the closest they came.
HT: Millwall 2-0 Burton Albion
Nigel Clough rolled the dice at the break as new signing Tyler Walker replaced Tom Naylor as the Brewers switched to a 4-4-2.
The Brewers couldn't get going in the second although Calum Butcher did have the ball in the net only to be ruled out for offside.
Brewers boss Nigel Clough made another substitution 15 minutes into the second half as Mason Bennett replaced Stuart Beavon which moved Lucas Akins up top with Tyler Walker.
Neither team really looked like scoring in the second half. Millwall thought they should have had a penalty 10 minutes from time as Gregory went down in the box under the challenge of Flanagan but the striker fell rather dramatically, nothing given.
Millwall could have made it three a few minutes from time as Gregory pick-pocketed Edwards before advancing towards goal, slipping Thompson the ball who could only fire straight at McLaughlin.
Clough tried one more roll of the dice late on as Harness replaced Duffy who did look very lively when he came on.
FT: Millwall 2-0 Burton Albion
Ash's man of the match: Calum Butcher