James Henry and Rob Hulse shattered Luton's FA Cup dreams to send Millwall through to the last eight with a 3-0 win at Kenilworth Road.
The Hatters had stunned the Norwich to make the fifth round three weeks ago, and at times on Saturday they looked more than capable of pulling off another big upset against a side ranked 67 places above them in the league ladder.
But Hulse, on loan from QPR, took his first strike for the club well, hooking the ball over Mark Tyler from a tight angle after Henry had put the Lions ahead following a mistake by Jonas Kovacs. Dany N'Guessan sealed the win with five minutes left.
Millwall's supporters let themselves down at one point in the second half by taunting the home fans with "Taliban" chants at Kenilworth Road. However, the one incidence of chanting was the only sour point of a typical FA Cup tie on a cold afternoon at the home of the Blue Square Bet Premier side.
Andre Gray played a clever one-two to open up some space in the Millwall box, but David Forde saved well from the lively striker.
Gray, and the impressive JJ O'Donnell raised the hopes of the home fans, but the visitors then took the lead through Henry. Robert Kovacs mis-judged the bounce of an aerial ball and the forward raced through and rounded Mark Tyler before slotting home from an acute angle.
Luton threw everything forward looking for an instant reply. Arnaud Mendy went close with two efforts, but the Hatters lacked Millwall's shooting ability.
Hulse tested Tyler with an acrobatic effort and the journeyman striker then made it 2-0 10 minutes before the break, hooking the ball over his shoulder from a tight angle after the ball had bounced around the home box.
Kovacs cleared the bar with a free header soon after as Luton continued to pressure, but it was Millwall who looked the more likely side to score.
N'Guessan made sure of the win five minutes from time when Tyler spilled John Marquis' shot and he turned home from close range.