Full-time score from The Den
Millwall's poor run in the Championship continued as Peterborough United handed out a 5-1 hammering to condemn The Lions to a fifth successive league defeat.
To compound a miserable night for Kenny Jackett's men, left-back Shane Lowry was shown a red card after 69 minutes for bringing down Dwight Gayle as he raced clear on goal.
Posh were excellent value for the three points and were ruthless in front of goal when the opportunities came their way.
"What can I say? We had an awful lot of the ball right the way through the game and didn't do enough with it," reflected Lions boss Kenny.
"There wasn't enough cutting edge up front. In terms of our defending we didn't have the awareness. Peterborough were capable of breaking right from the first minute; on the break they were incisive and looked like they had goals in them from start to finish."
Darren Ferguson's men showed their attacking intent from the start and broke the deadlock after seven minutes when George Boyd, who produced a virtuoso display for the visitors, picked out Lee Tomlin who thumped the ball into the roof of the net from a central position.
The Lions looked to be right back in it when James Henry brilliantly lofted the ball over Posh keeper Robert Olejnik for a 12th-minute equaliser and the game opened up nicely with both teams pushing forward.
Benik Afobe tested Olejnik with a snap-shot and then former Lion Michael Bostwick made a vital block to avert the danger from Liam Trotter's piledriver and the keeper did well to pluck the ball just as Karleigh Osborne was about to connect with it from a Henry corner.
But it was Posh, having weathered that little spell of Millwall pressure, who regained the advantage on 32 minutes when the irrepressible Boyd skipped past Adam Smith to set up Tommy Rowe and his crisp left-foot effort flew past Forde.
Jackett replaced both Smith and Afobe at the break with Martyn Woolford and Alan Dunne in a tactical switch that saw Henry move back to the right flank supported by right-back Dunne, and Woolford slotting in on the left wing.
However, within 10 minutes of the restart Posh further increased their lead to 3-1, although there was a hint of controversy about this one.
Ferdinand came away with the ball after a strong challenge that left Lions skipper Abdou floored, he picked out Boyd who in turned fed Tomlin, who had looked to be offside when the ball was originally played. Tomlin needed no invitation and slotted the ball home with the flag staying down.
Posh's fourth goal just five minutes later was the pick of the bunch when Nathaniel Mendez-Laing picked up the ball on the right-hand side, wriggled past Mark Beevers and Lowry before curling an exquisite shot from a near impossible angle into the top left corner.
Millwall looked to have reduced the arrears in the 67th-minute but Keogh's effort from close-range after Olejnik parried Abdou’s shot was ruled out for offside.
Matters went from bad to worse for The Lions when, with just over 20 minutes to go, Gayle broke free into the danger zone and was just about to pull the trigger when he was tripped by Lowry, who was shown a straight red card by referee Darren Bond, leaving the home team three goals and a man down with 21 minutes remaining.
Despite their numerical disadvantage, Millwall tried in vain to score and Olejnik athletically tipped Trotter’s header over from another Henry corner.
Posh put the seal on an impressive win in the final two minutes when Boyd was rewarded for his industrious display as he ghosted past Beevers and Osborne and poked the ball past Forde.
Millwall: Forde, A.Smith (Dunne, 46mins), Lowry, Abdou, Osborne, Beevers, Trotter, Hulse (Marquis, 84mins), Afobe (Woolford, 46mins), Keogh, Henry. Subs not used: M.Taylor, Wright, N'Guessan, Malone.
Lowry (18mins), Henry (62mins), Osborne (74mins)
Peterborough United: Olejnick, Zakuani, Bostwick, Tomlin (Newell, 90mins), Boyd, McCann, Rowe, Ferdinand (Payne, 86mins), Little, Gayle, Mendez-Laing (Swanson, 77mins). Subs not used: Alcock, Brisley, Day, Knight-Percival.
Scorers: Tomlin (7mins) Rowe (32, 55mins), Mendez-Laing (60mins), Boyd (88mins)
Ref: D. Bond
Att: 8,769 (away 379)