MILLWALL conceded goals in either half as they were deservedly beaten by Blackburn Rovers at Ewood Park on Saturday.
Derrick Williams gave the home side the lead in the 18th minute when he ran on to a pass from Greg Cunningham and fired a first-time shot past Bart Bialkowski from 22 yards.
Rovers goalkeeper Christian Walton saved low efforts from Ryan Leonard and Mahlon Romeo before the break.
Blackburn had a chance to go 2-0 up when Bradley Dack played Elliott Bennett in on the right side of the box, but the defender dragged a poor shot wide of the far post.
Bialkowski prevented Rovers from doubling their lead eight minutes into the second half when he dived low to his left to push away Stewart Downing's shot.
The Polish international stopper produced a better save moments later when he was quickly off his line to block Adam Armstrong's close-range effort.
After Bialkowski had saved again, this time from Dack, Connor Mahoney slipped Jon Dadi Bodvarsson in on the left side of the box and Walton saved the Iceland international's shot at the near post.
Leonard shot just over the bar in the 72nd minute but Rovers doubled their lead with 16 minutes left when Dack slotted in at the back post from Darragh Lenihan's cross.
Bialkowski tipped Joe Rothwell's shot around the post with 12 minutes left as Rovers continued to find gaps in the away defence.
Bialkowski had one final save to make, as he beat away Adam Armstrong's shot at the near post in injury-time, the last action of the game.
Bialkowski prevents worse beating
The goalkeeper was easily Millwall's best player at Ewood Park.
He kept his side in the game early in the second half with three good saves. In front of him his side struggled to prevent Rovers creating clear goal-scoring chances.
Bialkowski couldn't be blamed for the goals, one a rasping effort and the other a back-post tap-in.
Apart from the 4-0 defeat at Fulham, Millwall hadn't given away many chances in the Championship this season.
But Blackburn, through Dack and later substitute Rothwell creating and getting chances, could have won by an even clearer margin.
If in doubt, put it out
Williams' strike was fierce, giving Bialkowski little chance as the ball whizzed past his left hand. But the defender shouldn't have had the chance. Romeo wasn't under that much pressure from Bennett's cross from the right, but if he was unsure who was behind him he should have headed it out to give his side a chance to re-set from the corner.
Instead his back-header landed at Cunningham's feet, the left wing-back teed up Williams up from his left-sided centre-back post, and his shot was superb as he found the far corner.
Rovers' wing-backs cause visitors problems
To ensure you make the most of two wing-backs pushing high up the pitch, you have to have the players to find them. After Bennett and Cunningham combined for the opener, Dack put Bennett in behind Murray Wallace, but the finish didn't match the pass.
Rovers had chances to double their lead early in the second half, but were thwarted by Bialkowski.
And Tony Mowbray showed his and his players' tactical flexibility in the last 20 minutes when they switched to a back four.
Rovers got their second, this time Lenihan crossing from the right for Dack to finish.
Internationals get first league starts
Bodvarsson and Jayson Molumby had a productive international break. Both arrived in the summer not fully fit, but they deserved their first league starts here.
Bodvarsson set up an early chance when he crossed from the right side of the box, but Connor Mahoney couldn't sort out his feet to shoot and Blackburn cleared.
It was a difficult afternoon for the pair, as it was for their outfield team-mates.
Mahoney struggles to make an impact
In the first half the winger cut in from the left but sliced a right-footed effort wide.
He is still adjusting to what Millwall want from him, but he needs to be stronger on the ball. After he was brushed off it at one point in the second half, the ball was transferred to Dack who showed his strength to hold off a tackle a find Sam Gallagher.
Millwall didn't get many crosses into the box before Mahoney was taken off in the 58th minute, with Matt Smith coming on.
There were two changes from the 1-1 draw against Hull City, with Smith and Tom Bradshaw dropping to the bench Molumby and Bodvarsson.
Millwall: 4-4-1-1: Bialkowski; Romeo, Pearce, Cooper, M Wallace (Ferguson, 76); J Wallace, Molumby, Leonard (Bradshaw, 76), Mahoney (Smith, 58); Thompson; Bodvarsson.
Subs: Steele, Hutchinson, Williams, O'Brien.
Image: Millwall FC