The Iron extended their unbeaten run to seven matches, but had to settle for a 0-0 draw at Barnsley.The Good Friday clash saw Graham Alexander take charge for the first time, but United could not find a way through the Tykes defence.
That means that the Iron go into the last eight games eight points adrift of the top six.
Elsewhere in League One, Burton were held to a 0-0 draw by relegation threatened Oldham, meaning their lead is now cut to four points.
Wigan took full advantage as a five minute second half spell helped them to a comfortable 4-1 win at Swindon.
They led at half-time through Will Grigg, but goals from Max Power, Grigg again and Sam Morsy in a four and a half minute spell sealed the game.
Nicky Ajose grabbed the consolation for the hosts, who also had Nathan Thompson dismissed late on.
Neither third placed Walsall nor fourth placed Gillingham were in action on Good Friday, but Millwall failed to take advantage.
The Lions slipped to a late defeat to Bradford, with Steven Davies grabbing the only goal as the Bantams moved into sixth.
At the bottom, Colchester moved off the foot of the table and gave their survival hopes a boost as they beat Doncaster 4-1.
The visitors, also in relegation danger, took the lead through Iron loanee Gary McSheffrey, but Colchester changed the game with three goals in ten minutes.
Chris Porter, Gavin Massey and Alex Gilbey started the turnaround, with Richard Brindley adding a fourth late on.
That means Crewe dropped to the bottom of the table, but nearly grabbed a point in a thrilling match against Sheffield United.
Che Adams and Ryan Flynn put United 2-0 up, but David Fox and Harry Davis hauled Crewe level, only for Billy Sharp to grab a dramatic late winner.
Blackpool missed a great chance to pull themselves clear of the bottom four as they could only draw with Bury.
Danny Philliskirk gave them the lead from the penalty spot, but Danny Mayor equalised minutes later to ensure the points were shared.
Fleetwood and Chesterfield also edged themselves closer to safety as the pair played out a 0-0 draw on Saturday.
Meanwhile, Rochdale made it six wins in their last seven to continue their late push for the League One top six, beating Southend 4-1.
Jack Payne gave the visitors the lead, but it was in vain as Grant Holt, Joe Rafferty, Jamie Allen and Joe Bunney sealed a comfortable win.
Coventry’s poor form continued as they fell to a 3-1 defeat at Peterborough, with Michael Bostwick, Lee Angol and Harry Beautyman all on target.
Also, Sullay Kaikai was on target again as he netted Shrewsbury’s equaliser in their 1-1 draw at home to Port Vale.
Next up for the Iron is the visit of Swindon on Monday, with Graham Alexander hoping for a first win since taking charge.
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