Walsall's first double lifted them to sixth in the Coca-Cola League One table and warned Millwall that they face a huge test on their return to the Banks's Stadium for the third round of the FA Cup in a fortnight's time.
The Saddlers' second biggest victory of the season has put them in a play-off spot, and supporters worried that bids might come in for some of the young stars when the transfer window opens this week will be pleased to hear what manager Richard Money had to say on the matter.
"They are under contract to the end of the season and I am under no pressure to sell," he insisted.
"We don't need money, but I can't stop speculation. If clubs were not interested in one or two of them, I would be very surprised."
Rumours were circulating before the game that Leeds United, who scraped a draw with the Saddlers a week earlier, had put in a bid of £750,000 for left-back Daniel Fox.
The 21-year-old former Everton youth team player has been in great form, but missed the Millwall game through a one-match suspension.
That presented an opportunity for yet another Walsall youngster to make his full debut.
Richard Taundry, aged 18, showed remarkable composure in the defence, earning a tribute from Money.
"He played exactly as I thought he would. He is going to be some player," he said.
Taundry's arrival meant that seven former youth team stars were on the pitch at some stage in the game, a great tribute to the club's development policy.
But it was a veteran in the line-up who began the taming of the Lions. Tommy Mooney, the 36-year-old skipper, was in the perfect position to smash a volley into the roof of the net when Michael Ricketts headed down a deep ball from Rhys Weston in 29 minutes.
Weston, a former Arsenal player, is now producing the form that made him a big-money buy when Cardiff City took him from High-bury, and he was unlucky not to score with a blistering drive that drew a superb save from Lenny Pidgeley in the second half.
Mooney showed quick thinking again on 38 minutes, anticipating a mix-up between Millwall defenders Zak Whitbread and Marcus Bignot to round the keeper and drive in his ninth goal of the season.
It was just not Millwall's day. Gary Alexander and Ade Akinfenwa had both gone close to scoring during a reasonable start, but just before half-time Neil Harris had the misfortune to turn a Ricketts cross past his own goalkeeper to virtually end the contest.
To their credit, the visitors tightened up in the second half, though rarely looking capable of preventing Clayton Ince keeping his tenth clean sheet in the league.
With Darren Wrack giving a remarkable non-stop display of midfield drive, Walsall went looking for more goals, but Pidgeley made two more impressive saves to deny Mooney his hat-trick and substitute Edrissa Sonko his second goal of the season.
Ricketts, having been fighting influenza all week, was replaced at the start of the second half, and young midfielder Mark Bradley limped off after taking a nasty blow on the shin, but both should be available for the Boxing Day game at Staffordshire neighbours Port Vale, when Fox will also be eligible to return.
Millwall manager Kenny Jackett was very impressed by Walsall, and said: "They deserved the points. We continually tried to go through the middle against a well-drilled and very solid Walsall set-up who had some of the characteristics we lack."
So Money got his Christmas wish of three points at the start of an extremely heavy programme of matches. He has built a team that competes for everything and should go all the way in the promotion race.