The Gills took an interval lead through Danny Kedwell's penalty and though Bradley Dack was sent off for violent conduct in first-half stoppage time, they preserved their clean sheet and top spot.
Free-scoring Port Vale remain second after a 5-2 win over Fleetwood, who drop from third to fourth. Vale went ahead through the in-form Tom Pope and Ashley Vincent quickly doubled their lead. Junior Brown pulled a goal back but Pope's second restored the two-goal margin and Louis Dodds struck twice to make it 5-1 before Steven Gillespie's penalty provided a consolation.
Fleetwood were overtaken by Exeter, who twice came from behind to beat Wycombe. Gareth Ainsworth struck first for the Chairboys but the Grecians hit back through Arron Davies. Dean Morgan's looping header restored Wycombe's lead but was immediately cancelled out by Jamie Cureton before Danny Coles' goal sealed it.
Bradford's 3-1 win over Morecambe took them fifth ahead of Accrington, who were beaten 4-3 in a thrilling game at Chesterfield.
Rochdale ended Rotherham's unbeaten home record since moving to the New York Stadium with a helter-skelter 3-2 win.
Veteran Dele Adebola put Dale ahead on the stroke of half-time but Alex Revell equalised on the hour and five minutes later, Daniel Nardiello put the hosts 2-1 up. Bobby Grant's penalty levelled the game and Kevin McIntyre put the visitors ahead for the second time in the game with 11 minutes remaining.
Cheltenham inflicted a fourth defeat in a row on Oxford, Darren Carter and Shaun Harrad putting the hosts 2-0 up before Peter Leven pulled one back from the spot with 10 minutes remaining
Rene Howe gave Torquay a 1-0 win at AFC Wimbledon and Aldershot's Craig Reid scored the only goal against Barnet.
Northampton were also 1-0 winners thanks to Adebayo Akinfenwa's goal away to Dagenham while Plymouth and Bristol Rovers drew 1-1. Conor Hourihane put Plymouth ahead but Rovers equalised through Tom Parkes.
- Danny Kedwell
- Tom Pope