|Bamford 26, Kike 30, Vossen 78||Venue: Riverside Stadium
MILLWALL were outclassed by table-toppers Middlesbrough as they shipped three goals in a game for the 12th time this season.
Lee Gregory and Jos Hooiveld missed two gilt-edged chances for the Lions before Patrick Bamford's clinical strike broke the deadlock.
Kike's bundled finish made it 2-0 before the break and while Millwall held their own between the two boxes, they offered little up front and Jelle Vossen scored a third.
The result keeps Ian Holloway's side six points adrift of safety.
Despite defeats to Sheffield Wednesday and Rotherham, Holloway named an unchanged side for the third successive game.
That was made possible after Diego Fabbrini passed a late fitness test, having been substituted against the Millers on Saturday with a muscle strain.
Millwall were still reeling from their weekend defeat at the New York Stadium but their fragile confidence didn't show as they dominated the early possession.
They created a half-chance in the 15th minute when Jimmy Abdou's inviting first-time cross was flicked on by Gregory at the near post but there was nobody running in behind him to bury the loose ball.
Gregory, who has failed to convert a string of clear-cut chances in recent weeks, was then put through on goal by Gary Taylor-Fletcher's flick-on but he couldn't beat Dimi Konstantopoulos in the Boro net.
At the other end, Lee Tomlin was denied the opener by Shaun Williams' flying block on the line.
The Lions' encouraging start continued and after Fabbrini was brought down, Michael Tonge's well-struck free kick was deflected behind for a corner.
Tonge swung over the set-piece which, following a touch from Gregory, fell kindly to Hooiveld inside the six-yard box but his instinctive shot went straight at Konstantopoulos.
The game then followed a pattern very familiar to Millwall fans as, 30 seconds later, Albert Adomah's pass was dummied to Bamford, who crashed a high drive into the top corner to make it 1-0.
Boro added a second goal within four minutes as Bamford controlled a long pass forward before teeing up Kike, whose awkward finish looped agonisingly over David Forde and into the net.
Shaun Williams fired wide from distance and Martyn Woolford twice did the same in the closing stages of the first half, which petered out following the hosts' goal rush.
A chance fell Dan Harding's way early in the second period but after getting goal-side of the Boro defence, his cross-shot was hacked behind for a corner, from which Taylor-Fletcher headed over.
Grant Leadbitter headed over the bar from Adomah's cross before the duo reversed roles and Adomah fired straight at Forde from Leadbitter's set piece.
Substitute Ed Upson had a rare effort on goal for the visitors when a quick exchange of passes played him into space 25 yards out, but his shot whistled just past the post.
And the Teessiders put the game to bed in the 78th minute when Jelle Vossen tapped in the rebound after George Friend's initial effort had been parried.
Former Den loanee Ryan Fredericks could have added a fourth goal late on but he blasted over from a good position inside the box.