The 5-2 humiliation at Oakwell means the Iron have now taken just one point from their last six games.
Barnsley, on the otherhand, are in-form and move up to fourth thanks to their win.
Gillingham moved above Scunthorpe in the table thanks to a 3-0 win over Port Vale, while Hartlepool are up to 12th thanks to a 2-1 win over Bournemouth.
Rotherham manager Mick Harford was sacked after a 2-1 reverse at the hands of Yeovil.
Huddersfield missed the chance to close the gap on leaders Swansea after a surprise defeat at lowly Bristol City.
Swansea were held to a 1-1 draw by Colchester, with Andy Robinson equalising Chris Iwelumo's opening goal.
But Bristol City hauled themselves off the foot of the table thanks to a 2-0 home win over the Terriers.
Scott Murray and David Cotterill scored either side of the break to end a miserable nine-game losing sequence for the Robins.
Swindon replace them in the bottom spot after a 2-2 draw at Oldham - where they lead by two goals.
Brentford stay third after a 1-1 draw with Chesterfield, while Southend were also held 1-1 by Bradford at Roots Hall.
Walsall had Ishmel Demontagnac red carded against Nottingham Forest, but still held on for a point at the City Ground after a 1-1 draw.
Doncaster beat MK Dons 3-2, while Blackpool earned a valuable point against Tranmere thanks to Peter Clarke's last-minute equaliser.