News of a £250,000 cash injection by pop superstar Robbie Williams warmed Vale's hearts on a bitterly cold night in the Potteries.
And all appeared to be going well for the home side as Tony Dinning clattered a shot against former Vale goalkeeper Paul Musselwhite's right-hand post early on.
But the contest burst to life after Scunthorpe took an 11th minute lead through a cracking strike by Matt Sparrow.
There appeared little danger when Sparrow cut in from the left but he unleashed an unstoppable 25-yard shot which raced into the top left-hand corner of Mark Goodlad's net.
It got worse for Vale three minutes later when home debutant Jason Talbot received a straight red card for a violent tackle on Richard Hinds.
Scunthorpe manager Brian Laws was banished to the stands after attempting to get on to the field to confront Talbot and then exchanging angry words with his Vale counterparts.
Vale's 10 men were initially galvanised by the uproar and they netted an 18th minute equaliser when Michael Cummins bundled Jeff Smith's inswinging free-kick over the line.
But the Vale goal had a miraculous escape in first-half stoppage time as Goodlad brilliantly turned Steve Torpey's header against the underside of the bar and Nathan Stanton hammered a shot against a post.
Scunthorpe's pressure intensified after the interval and Vale's defence was finally breached again when man-of-the-match Cleveland Taylor struck a ferocious shot from 20 yards into the roof of the net just before the hour.
Vale certainly didn't throw in the towel and hit back as Leon Constantine's shot struck the bar before Scunthorpe hit the woodwork twice more through Sparrow and Andy Keogh in the closing stages.