TEN-MAN Barnsley were dumped out of the FA Cup at the third round stage after a thrashing away at Millwall.
The Reds started brightly and even took the lead through Brad Potts' early strike.
But Millwall were stirred after conceding and scored three times after the break to capitalise on Joe Williams' reckless sending-off.
The Reds haven't now progressed beyond the third round in five seasons - when they reached the quarter-finals before being thrashed 5-0 by Manchester City.
Here, Barnsley made a bright start and were soon in front after 11 minutes.
Potts - one of two changes - smashed home inside the area after a fine assist from Adam Hammill.
But Millwall then proceeded to up the ante and after going close with a couple of half-chances, they were back on level terms.
Aiden O'Brien found space inside the box before picking his spot to squeeze a shot past Adam Davies on 35 minutes.
The Reds got a big let-off just before the interval when Jed Wallace was in acres of space at the back-post but somehow prodded wide of Davies' goal.
But there was no escape just two minutes after the restart when Ben Thompson swept home from ten yards out.
And it went from bad to worse for the visitors on 52 minutes when they were reduced to ten men.
Everton loanee Williams lunged into a challenge with Wallace but was shown a straight red by referee Darren Bond.
The Lions took full advantage and O'Brien soon notched his second of the afternoon on 56 minutes with a superb strike long-range that Davies couldn't get near.
Fred Onyedinma then got in on the act just after the hour mark when he rounded Davies and tapped in a fourth.
Despite their efforts Barnsley couldn't fashion an unlikely comeback as they exited the world's oldest cup competition at the first attempt.
Millwall: Martin, McClaughlin, Hutchinson, Craig, Williams, Thompson, Onyedinma (Romeo 85), Wallace (Twardek 75), Morison (Gregory 72), O'Brien, Cooper
Subs not used: Archer, Meredith, Tunnicliffe, Saville
Barnsley: Davies, Cavare, Pinnock, Lindsay, McCarthy, Gardner, J Williams, Potts (Mallan 73), Isgrove (Moncur 64), Hammill (Thiam 64), Bradshaw
Subs not used: Townsend, Brown, B Williams, Smith