Coventry opened up a five-point lead at the top of Sky Bet League One as they heaped further pressure on Ipswich boss Paul Lambert in a 1-0 win at Portman Road.
Matt Godden's 15th league goal of the season - a cool finish past Will Norris in the 16th minute - proved the difference between the two sides, as Ipswich slipped to a fourth straight defeat.
The Tractor Boys had been among the division's early pacesetters and their latest disappointing result will lead to further questions about Lambert's future, with Neil Warnock having been linked to the post this week.
Rotherham lost ground on the table-topping Sky Blues in a 3-1 defeat at Rochdale, who boosted their own battle against relegation.
The Millers were unbeaten in seven matches but were undone by two goals from Ian Henderson and a third from Matty Lund, before Jamie Lindsay pulled one back for Rotherham late on.
Oxford propelled themselves from seventh to third with their fifth consecutive win - a 3-2 victory at Shrewsbury - while Peterborough enjoyed a similar jump thanks to a 2-0 triumph over Portsmouth, who dropped from third to sixth.
Sunderland twice took the lead in a 2-2 draw with Gillingham, while Fleetwood dropped out of the play-off positions after failing to get the better of Blackpool - under new boss Neil Critchley - in their goalless derby clash at Highbury.
It was an encouraging day for clubs at the bottom end of the table, with none of the bottom five tasting defeat.
Southend halted a miserable run of six straight defeats with a 3-1 win against Bristol Rovers at Roots Hall.
Charlie Kelman and Terrell Egbri scored either side of Jayden Mitchell-Lawson's effort for Rovers, before Alfie Kilgour's own goal made sure of the three points for Southend.
Tranmere made it back-to-back wins in a 2-1 victory at Accrington, meaning bottom club Bolton's goalless draw at AFC Wimbledon was not enough to see them gain ground on the teams above them.
In the day's remaining matches, Lincoln came out on top in an entertaining 3-2 win over Burton, with Josh Vickers saving a late penalty for the victors, while Doncaster won 1-0 at MK Dons.