The Iron fell to a 2-1 defeat at Gillingham, with a last minute strike ending a run of three consecutive wins.
Scott Laird’s second in as many games had given United the lead, but Brennan Dickenson and Harry Lennon turned the game around for the Gills.The hosts also had Josh Wright sent off nine minutes before the finish, but won to remain top of the League One table, with the Iron dropping to 17th.
They are closely followed in second by Walsall as they secured a comfortable 2-0 win away at Barnsley, who have now suffered four straight defeats.
Goals from former Iron loanee George Evans and Milan Lalkovic sealed the victory and kept Walsall two points off the top.
Burton remain third, despite a 0-0 draw at home to Crewe, who are still rooted to the bottom of the League One table.
Coventry could not take advantage though as they drew 0-0 with Rochdale. The Sky Blues have not conceded in any of their last four league games.
It was a good night for Sheffield United as they moved up to fifth and gained ground on their rivals, winning comfortably at home to Fleetwood.
Youngster Che Adams netted a brace and Billy Sharp added a third, with Fleetwood slipping back into the bottom four as a result.
Bury dropped to sixth as they suffered only their second defeat of the season, losing 2-1 away to Bradford.
Rory McArdle opened the scoring for the Bantams, with a Reece Brown own goal doubling their advantage. Danny Rose pulled one back for Bury.
Wigan continued to make ground on the play-offs, but had to survive a scare at Peterborough before they eventually won 3-2.
Yanic Wildschut and Will Grigg gave them a comfortable lead, but Erhun Oztumer and Souleymane Coulibaly levelled for the Posh.
It proved to be short lived as Max Power restored the Wigan advantage a minute later to put them within one point of the top six.
At the bottom, Swindon’s fourth defeat in a row saw them drop to 23rd in the table. They fell to a 2-1 defeat against Oldham in their first game without ex-manager Mark Cooper.
Chairman Lee Power took charge and looked to have secured a point when Nicky Ajose cancelled out Mike Jones’ opener, only for Danny Philliskirk to score a late winner.
Blackpool are also is the bottom four, but continued their recent revival with a 1-1 draw at home to Millwall, although the visitors finished with ten men.
Darren Ferguson won his first match in charge of Doncaster, with Keshi Anderson getting a late winner to defeat Shrewsbury 2-1.
Meanwhile, Sylvain Ebanks-Blake netted twice to inspire Chesterfield to a 3-0 win at home to Southend, leaving both sides just outside the play-offs.
Plus, Colchester returned to winning ways as they beat Port Vale 2-1, ending a sequence of three consecutive defeats.
Next up for the Iron is a trip to Chesterfield, and Mark Robins will hope that his side can bounce back with a victory.
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