Chesterfield had been due to play Northampton but it was one of four matches that fell victim to waterlogged pitches.
Burton also jumped ahead of Chesterfield despite being held to a goalless draw by Mansfield.
Ryan Leonard was Southend's hero as they climbed to fourth with a 2-1 victory over Portsmouth.
Sonny Bradley gave the visitors the lead on the half hour but Leonard levelled just before half-time and netted the winner two minutes into injury time.
Fleetwood moved back into the play-off places after ending a three-match losing run with a 3-1 win over Accrington.
Torquay stay in the bottom two after a 2-0 defeat by Plymouth, Caolan Lavery (60) and Lewis Alessandra (85) scoring the goals.
Morecambe missed the chance to close the gap to the top seven, losing 1-0 to a 30th-minute goal from Ryan Jarvis for York.
Dagenham & Redbridge are now only one point behind the Shrimps after beating AFC Wimbledon by the same scoreline.
Abu Ogogo scored the only goal in the 10th minute and the Daggers held on despite losing Lawson D'Ath to a second yellow card with more than half an hour to go.
It was a miserable day for Hartlepool, who were two down inside 12 minutes at home to Bury.
Danny Mayor and Daniel Nardiello struck early and Richard Hinds wrapped up a 3-0 win in the 75th minute.