MK Dons suffered a setback in their quest for automatic promotion from League One after Gillingham edged a dramatic six-goal encounter at the Priestfield Stadium.
Ben Reeves restored parity with a penalty midway through the second period, but goals from full back Bradley Garmston and John Marquis gave the Kent outfit their second win under new manager Justin Edinburgh and kept the Dons outside the top two places.
Chesterfield missed the chance to move into the top six after relegation-threatened Leyton Orient came from behind before Dean Cox scored in the 11th minute of injury time to seal victory for the visitors at the Proact Stadium.
Oldham Athletic stay above Chesterfield, but lost at home to another candidate for the drop, Colchester United. Sammie Szmodics's second-minute strike proved enough for the Essex outfit to move to within a point of Coventry City.
Rochdale are five points off a playoff place, but have dropped to 15th in the table following their 2-1 defeat at Peterborough, with early goals from Harry Beautyman and Christian Burgess proving enough to extend Posh's recent resurgence.
Results in full: Bristol City 1–3 Sheffield United, Chesterfield 2–3 Leyton Orient, Crawley Town 5–1 Barnsley, Crewe Alexandra 2–0 Fleetwood Town, Doncaster Rovers 3–0 Yeovil Town, Gillingham 4–2 MK Dons, Oldham Athletic 0–1 Colchester United, Peterborough United 2–1 Rochdale, Scunthorpe United 3-1 Swindon Town, Walsall 0-1 Port Vale