The visitors secured progression to the final eight of the FA Cup for the first time since they were finalists in 2004 with a comfortable win over their non-league opponents.
First-half goals from James Henry and Rob Hulse, and a second-half strike from Danny N’Guessan ensured the Lions progressed to the last eight of the tournament for the first time since they were beaten in the 2004 final by Manchester United.
It was the visitors who had the first clear chance of the game after just two minutes, as veteran striker Hulse beat the offside trap to find himself 1-on-1 with Hatters keeper Mark Tyler, but the QPR loanee could only drag his shot wide of the far post from 16 yards out.
LUTON 0-3 MILLWALL
It was the Championship side that got the first goal of the game after 11 minutes when Henry capitalized on a woeful mistake from Luton defender Janos Kovacs. The Hungarian center back failed to control a simple pass, and the quick-witted Henry pounced on the loose ball, before advancing on goal and rounding the stranded Tyler to put the Lions ahead.
The non-leaguers almost bounced straight back through Arnaud Mendy, when the midfielder reacted quickest to a headed knock-down in the area to lash a shot towards goal, but Forde reacted well and beat his effort away to safety.
Millwall then began to take control of proceedings, and it came as little surprise when the Lions grabbed a second goal 10 minutes before halftime. It came through Hulse, who more than made up for his earlier miss with a wonderful volleyed effort from just inside the 6-yard box.
Henry did well in the build-up down the right and hung a cross towards the far post where Hulse first won a header, before finding the net with an improvised overhead kick which nestled into the bottom corner of Tyler’s net.
Millwall’s hunt for a decisive third continued as the game wore on, and with just five minutes left, the Lions made the result safe when N'Guessan reacted quickest to a fumble from Tyler to stroke home from close range and ensure the scoreline gave a more accurate reflection of the game's proceedings and put the club in the quarterfinals of the competition while ending Luton Town's improbable run.