Match ends, Millwall 2, Wigan Athletic 1.
Millwall condemned Wigan to a fifth straight defeat as incoming Latics manager Uwe Rosler watched his new side from the stands.
The Lions took an early lead when Steve Morison fired in from close range after a goalmouth scramble.
The south Londoners doubled their lead seven minutes from time when Jermaine Easter calmly slotted home.
James McArthur instantly pulled a goal back with a strike from the edge of the box, but the Lions held on.
Rosler, who will officially start work tomorrow after replacing Owen Coyle as Wigan boss, was given an indication of the size of the job facing him.
Millwall pushed forward from the kick-off and had a penalty appeal turned down in the opening minute when Stephen Crainey appeared to pull down Liam Feeney.
The Lions remained on the attack and Morison put them ahead when the ball fell to him after the Latics defence failed to clear a corner.
There was some encouragement for Rosler when James McClean twice forced Millwall goalkeeper David Forde to make sharp saves.
But the hosts nearly doubled their lead on 34 minutes when Martyn Woolford saw his shot crash back off the post.
As Millwall became nervier in the closing stages, the Latics grew in confidence and Grant Holt twice came close to getting on the end of crosses.
But it was Steve Lomas's side who got the crucial second goal, Easter firing past Scott Carson after reaching Liam Trotter's long ball on the counter-attack.
McArthur pulled a goal back a minute later with a shot from just outside the area, but the Lions dug in and extended their unbeaten home run to seven games.
Millwall manager Steve Lomas:
"We like to make things difficult for ourselves. At 2-0 you think the game has been put to bed and then they get a chance straight away and then we were just hoping we could withstand the pressure and we did.
"It would have been unjust if we didn't get the three points.
"Wigan had a right go and they've got some good professional players there. We knew with their quality they would probably have quite a bit of possession but were always a danger on the counter."
Wigan caretaker manager Graham Barrow on new Wigan boss Uwe Rosler:
"I think it's just the attacking side which needs working on and with Uwe having been a top striker maybe he can help us with that and the movement of the players.
"Uwe came in the dressing room before the game, at half-time and full-time and he will be in the club tomorrow.
"He seems a very positive man and I'm looking forward to working with him.
"The whole club is excited about Uwe coming in. The players have been great all along but you could tell that they'd been given a lift."
- 7FeeneySubstituted forKeoghat 67'minutesBooked at 90mins
- 29WaghornSubstituted forEasterat 78'minutes
- 17BoyceSubstituted forShottonat 77'minutes
- 3CraineyBooked at 58minsSubstituted forEspinozaat 80'minutes
- 19PowellSubstituted forMcManamanat 54'minutes
- 14Gómez García-Penche
- Scott Duncan
- Shots on Target
Second Half ends, Millwall 2, Wigan Athletic 1.
Andrew Keogh (Millwall) is shown the yellow card for a bad foul.
James McArthur (Wigan Athletic) wins a free kick on the left wing.
Foul by Andrew Keogh (Millwall).
Attempt missed. Iván Ramis (Wigan Athletic) right footed shot from the centre of the box is high and wide to the right. Assisted by James McClean with a cross following a corner.
Corner, Wigan Athletic. Conceded by David Forde.
Attempt saved. Leon Barnett (Wigan Athletic) header from the centre of the box is saved in the top right corner. Assisted by James McArthur.
Corner, Wigan Athletic. Conceded by Mark Beevers.
Attempt blocked. Callum McManaman (Wigan Athletic) right footed shot from the centre of the box is blocked. Assisted by Grant Holt with a headed pass.
Corner, Millwall. Conceded by Scott Carson.
Attempt saved. Steve Morison (Millwall) right footed shot from the left side of the box is saved in the bottom left corner. Assisted by Andrew Keogh.
Corner, Wigan Athletic. Conceded by Andrew Keogh.
Foul by Ryan Shotton (Wigan Athletic).
Paul Robinson (Millwall) wins a free kick on the right wing.
Foul by Leon Barnett (Wigan Athletic).
Jermaine Easter (Millwall) wins a free kick on the left wing.
Goal! Millwall 2, Wigan Athletic 1. James McArthur (Wigan Athletic) left footed shot from outside the box to the bottom left corner. Assisted by Ryan Shotton.
Goal! Millwall 2, Wigan Athletic 0. Jermaine Easter (Millwall) left footed shot from the left side of the box to the bottom right corner. Assisted by Liam Trotter with a through ball following a fast break.
Substitution, Wigan Athletic. Roger Espinoza replaces Stephen Crainey.