The pacesetters had seen their nine-match winning streak ended by lowly Shrewsbury in a goalless draw at the weekend and there was more disappointment for Kenny Jackett's men as they failed to hold on to a lead at mid-table Crawley.
James Henry's 25th-minute strike put the visitors ahead but Crawley were level within two minutes thanks to Billy Clarke, and just five minutes after that Matt Tubbs slotted home what would prove to be the winner.
In Tuesday's other game, second-bottom Shrewsbury could not follow up their draw at Molineux with another good result as they were beaten 1-0 at Colchester, Jabo Ibehre netting the only goal 11 minutes into the second half.
Jabo Ibehre's well-taken goal gave Colchester a vital 1-0 win over fellow strugglers Shrewsbury at the Weston Homes Community Stadium.
Colchester went ahead in the 56th minute when Ibehre kept possession in the area before planting a low shot inside the far post from Alex Gilbey's pass.
Shrewsbury pressed for an equaliser after that but Colchester held out for a crucial three points.
- Sports & Recreation
- Kenny Jackett