Only 3,452 fans, including 466 from Blue Square South side Staines, bothered to turn up for this second- round replay for the right to host Championship side Derby.
Not even Millwall boss Kenny Jackett made it, suffering a sore throat - but on this occasion it was no Jackett required.
Strike one: Steve Morison curls in Millwall's first goal against the Blue Square South opponents
FA Cup: Staines 1 Millwall 1- Ali C makes it massive day for the SwansLeeds 5 Kettering 1: Whites through to face Manchester United after late showESPN seal four-year deal to show FA Cup following collapse of SetantaBarrow 3 Oxford 1: Non-league battlers book third round trip to SunderlandMaybe the stay-aways knew something as League One Millwall struckeither side of the interval and pulled away for a straightforwardfour-goal victory against a side 78 places beneath them in football'spyramid.
Millwall didn't even bother to open one stand and behind one of thegoals was assembled a hardy bunch of around 200 Staines fans in theupper tier.
At least Millwall's much maligned fans were given asecond-half laugh when an unruly Staines fan was ejected by police.
Staines had knocked out Shrewsbury on their own ground and then heldMillwall 1-1 12 days ago - but few teams get a second chance of turningover Millwall, especially at The New Den.
Tough Staines: Jimmy Abdou goes to ground under pressure from Danny Gordon (left) and Simon Jackson (right)
Only Wycombe have managed it this season and, though Staines set outto frustrate the life out of them, their challenge died in the 40thminute.
That was when Steve Morison cut through the centre of the defence onto a ball from substitute Ashley Grimes and clipped it underneathadvancing keeper Louis Wells.
Suddenly, the well-drilled Staines two rows of four had to be disbanded to create some attacking moves.
But in the 50th minute, Millwall's left back Jack Smith seized on apass from Morison and turned to ram an angled shot into the far rightcorner of the net.
Wells saved bravely at the feet of Grimes as Millwall threatened to run away with it.
It was 3-0 on 79 minutes when Danny Schofield won a corner anddelivered it for right back Alan Dunne to head into the roof of thenet.
Schofield made it 4-0 himself in time added on, lashing the ball in from out on the left.
The closest Staines came to causing a surprise was a snap shot from Ali Chaaban.
Millwall assistant manager Joe Gallen said: 'Now we've got Derby inthe third round at home and we believe we can win. But ourconcentration now is on our home game with Walsall on Saturday and weneed to win to get back towards the top six.'
East-side: Leroy Griffiths (left) of Staines contests with Millwall goalkeeper David Forde
Millwall will certainly hope for more backing than they receivedlast night, when Staines must have been surprised by the lack of homesupport they faced, especially with one stand empty.
Gallen added: 'We knew that if we scored first, Staines would haveto push more men forward and there would be more space for us to getthe goals.
'Our boss Kenny Jackett is not well. He left it till the lastminute but decided he couldn't come. I'm sure he watched it on theinternet site.
'I'm pleased I've got some good news to tell him when I speak to him.'
FA Cup: Staines 1 Millwall 1- Ali C makes it massive day for the SwansLeeds 5 Kettering 1: Whites through to face Manchester United after late showESPN seal four-year deal to show FA Cup following collapse of SetantaBarrow 3 Oxford 1: Non-league battlers book third round trip to Sunderland