The Iron suffered a 4-0 defeat at high-flying Charlton Athletic at The Valley on Easter Monday.
Anfernee Dijksteel scored his first goal in Charlton colours to open the scoring in the first half, before further strikes from Joe Aribo, Igor Vetokele and former Iron striker Lyle Taylor rounded off the scoring in the second period.
Caretaker manager Andy Dawson made five changes from the side that drew 0-0 with Blackpool at Glanford Park on Good Friday.
Cameron Borthwick-Jackson made his first start since the end of January after recovering from a knee injury which kept him out for three months. He replaced Tom Pearce in the starting eleven. Elsewhere, Clayton Lewis started as he came into the team for Levi Sutton.
Josh Morris also started after returning from the bench on Friday following a broken leg. He replaced Jordan Hallam. George Thomas and Lee Novak also came into the starting line-up in place of duo Kevin van Veen and Kyle Wootton.
Charlton, who had already secured a place in the play-offs before kick-off, came forward early on and had the game's first opportunity within five minutes. Albie Morgan found space on the left-hand side, before he drove into the area, however his final shot was fired into the side netting and didn't trouble Jak Alnwick.
Naby Sarr then tried his luck with a speculative shot from distance as he ran the ball out of defence, although his effort went high and wide of the target.
Rory McArdle then superbly denied Igor Vetokele, as he produced a fantastic slide tackle to block the shot and cleared for a corner, which the Iron then dealt with.
However, on 24 minutes, the home side did manage to make a breakthrough. Anfernee Dijksteel netted for the hosts, as he latched onto a throughball inside the area. He controlled it well, before he drilled his effort into the bottom left corner.
The Iron looked to hit back quickly though. Funso Ojo was teed up by Josh Morris 25-yards out and as the Belgian shifted the ball onto his right-foot, he looked to bend his effort back into the left post, although Dillon Phillips dived to his right and held onto the shot.
With ten minutes to go before the end of the half, Ben Reeves hit a left-footed shot over the crossbar, before Adam Hammill dragged his effort wide of the post for the Iron, after Lee Novak's high pressure set up a chance for a quick counter attack.
On 43 minutes, Phillips made a fine save at his near post to stop the Iron from equalising. Hammill laid the ball off to George Thomas with a brilliant reverse pass, the attacker then struck his shot well, but was denied by the strong hands of the Charlton goalkeeper.
Then, as the fourth official signalled for four additional minutes at the end of the first half, Dijksteel nearly added to his tally when his deep cross almost found the top left corner of the net, but Alnwick was alert and tipped the ball over the bar.
Deep into stopagge time, Ojo had another chance to level the scores for the Iron. Hammill had possession on the left flank and picked out Novak in the area. The striker then knocked the ball down to Ojo, who found space to run onto the ball, but somehow fired his right-footed shot wide.
As the teams emerged for the start of the second half, Charlton came out of the blocks in similar fashion to the first. Midfielder Josh Cullen had the first shot of the half from the edge of the area, but his curling effort missed the target.
Morgan then saw his acrobatic kick run into the gloves of Alnwick, before the Iron then had a chance through Novak, who struck a low Morris cross just wide.
United were still pushing for an equaliser and nearly found it when Hammill's dangerous ball almost found Novak, but the striker couldn't get a good connection and the ball fizzled out for a goal-kick.
However, as the Iron went in search of a goal, Charlton were able to hit them on the break and doubled their lead in the 57th minute from a corner when Joe Aribo headed past Alnwick to make it 2-0.
Former Iron striker Lyle Taylor then brought the ball under control in the area, before cutting back onto his left-foot, but as he tried to get his shot away, it was charged down well by a number of United shirts who surrounded him to clear the danger.
Just past the hour mark, Charlton made it three. Aribo, full of confidence from scoring moments before, slipped in Vetokele on the inside left of the area, who then poked the ball into the right corner of the net.
A few minutes later, Taylor did score against his former club with a well-struck free-kick that flew past Alnwick, leaving him with no chance.
With 20 minutes to play, Thomas had a great opportunity to pull a goal back for the Iron. Substitute Kevin van Veen delivered a deep cross to the back post from the left that picked out Thomas perfectly, but as he shot on the volley, his effort flew over the bar.
Matthew Lund was then sent on for the Iron for his first appearance since having a clear-up operation on his knee, as he replaced Clayton Lewis.
Moments later, van Veen looked to cause problems again. He dribbled past two Charlton defenders, before striking the outside of the post with his shot.
As the clock ticked through the final ten minutes, Borthwick-Jackson struck a sweet shot from distance which forced Phillips into making a save, but he only parried as far as Novak. However, on the follow-up, he couldn't direct his header on target.
There were another four additional minutes at the end of normal time, but no other chances were created and the Iron fell to defeat at the Valley.
Charlton Athletic: Phillips, Dijksteel, Bauer (C), Taylor, Reeves, (Pratley, 72), Vetokele, (Williams, 65), Purrington, Aribo (Forster-Caskey, 79), Morgan, Sarr, Cullen.
Substitutes not used: Maxwell, Pearce, Lapslie, Parker.
Scunthorpe United: Alnwick, Borthwick-Jackson, Webster, Ojo, Morris (Hallam, 82), Perch, Lewis (Lund, 74), Novak, Thomas, McArdle (C), Hammill (van Veen, 64).
Substitutes not used: Flatt, Sutton, McGahey, Wootton.
Referee: Brett Huxtable.
Attendance: 11,973 (309 away).