It was to be a disappointing evening for Mark Bonner's side as Cambridge slipped to second in the table with Cheltenham Town taking top-spot, recording a one nil home victory over strugglers Southend United.
But it was the away side who left the happier of the two with the win lifting The Iron 12 points clear of the relegation zone, with 16 games left to play.
Story of the match
It was very much a smash and grab performance for Scunthorpe United as the hosts dominated possession for large parts of the game but failed to really test keeper Mark Howard.
The first half was an even contest, with both sides enjoying large spells of possession, The U's undoubtedly creating the better of the chances.
Paul Mullin was a constant thorn in Scunthorpe's side as his tireless running behind the back line resulted in pegging Neil Cox's side back within their own half for large spells of the game.
Mullin's deflected cross on fourteen minutes fell kindly to Shilow Tracey on the edge of the area after Jordan Clarke had cleared off the line, but his subsequent effort was smartly saved by Mark Howard.
The home side again came forward on 17 minutes, as Liam O'Neill linked up with the energetic Mullin - but his low cross evaded the arriving Joe Ironside.
With the game locked at 0-0 as half time approached, Scunthorpe carved out their only real opportunity of the first 45 when the ball fell kindly to Kevin Van Veen, who blasted over from 25 yards.
As the teams returned following the interval, it was again the league-leaders who piled on the pressure, with Mullin again involved, his looping cross teased towards the back post but Ironside again couldn't connect as Howard collected smartly.
Shilow Tracey was another who caused constant problems across the evening, his teasing run on 55 minutes, forced Scunthorpe to concede another corner which subsequently came to no avail.
Minutes later Junior Brown hacked down Jack Iredale right on the edge of the area with a guilt edged chance teetering for Cambridge.
His subsequent free kick was hit hard and low and again Iron shot-stopper Mark Howard did well to keep the tie scoreless.
On 66 minutes the best chance of the game went to the hosts, as Mullin raced through on goal following Iredale's smart lofted through pass but he smashed his effort wide and the game again hung in the balance for both sides.
But just 13 minutes later it was joy for the away side, who entered the tie on the back of two successive defeats.
Devarn Green did superbly to press U's defender Declan Drysdale, and with the ball falling kindly to Alfie Beestin, he drove into the Cambridge area and placed his left footed effort past the on looking Callum Burton.
And hang on did they, with 7 minutes added on, Cambridge failed to muster up one last chance, as Scunthorpe hung on for a valuable away win.
Man of the match: Alfie Beestin
It was only to be one man, the 23-year-old's strike just 11 minutes from time was to be the deciding moment of the game and left Mark Bonner's side rueing missed chances as they slipped to second in the table.