League One leaders Hull were held to a 1-1 draw at struggling Oxford on Saturday.
Oxford, last season's play-off finalists, are labouring in the relegation zone this season, but took the lead through an early James Henry effort at the Kassam Stadium.
Hull hit back in the second half, however, as Greg Docherty earned them a point.
Lincoln are in second after a comfortable 2-0 win at Rochdale, thanks to goals from Jamie Jones and Lewis Montsma.
Ipswich are in third after they came back to beat Plymouth. Luke Jephcott put Argyle ahead at Home Park, but a Danny Mayor sending off cost them, with goals from Jon Nolan and Kayden Jackson sealing victory for the Tractor Boys.
Portsmouth leapfrogged Peterborough into fourth after seeing them off at Fratton Park. Jack Whatmough and Tom Naylor secured a 2-0 win for Pompey, as the Posh sunk to fifth.
Charlton are sixth despite being held late on by Shrewsbury. The Addicks seemed to be heading to victory through Ben Watson, but Oliver Norburn scored a late penalty to secure a 1-1 draw.
Accrington moved into seventh with a 2-1 win over MK Dons, while Doncaster are eighth after a 2-0 win at 10-man Northampton.
Lee Johnson's first game in charge of Sunderland ended in disappointment as they fell to a 1-0 home defeat against Wigan - who remain rooted to the bottom of the table despite that victory. The Black Cats are ninth, while Fleetwood are 10th after losing 1-0 at home to rivals Blackpool.
Elsewhere, Bristol Rovers won 4-2 against AFC Wimbledon in an entertaining game at Plough Lane, Burton and Crewe drew 1-1, and Gillingham beat Swindon 2-0 in Saturday's early kick-off.