In a great day for the top sides, Norwich and Sheffield United left it late to record home wins, while Reading and Preston scored away victories to stay in touch at the top.
Portsmouth were tested all the way at Fratton Park against plucky Walsall, although two Danny Sonner penalties were not enough as Pompey edged a 3-2 win.
Nigel Quashie fired in a volley to cancel out Sonner's first spot kick before Svetoslav Todorov put the home side ahead.
Sonner's second penalty drew the sides level once more, only for Matthew Taylor's strike to win for the leaders to maintain their lead at the top of the table.
Leicester City got off to the perfect start at Blundell Park as James Scowcroft gave them the lead from close range after just a couple of minutes.
Frank Sinclair then got himself sent off for two bookings in two minutes to put The Foxes on the back foot, and The Mariners made the extra man count just a few minutes later when John Oster levelled the scores on 54 minutes.
With Leicester seemingly hanging on for a point, Muzzy Izzet then pulled a wonder goal out of nowhere after 74 minutes to seal a well-earned victory for Micky Adams's side.
Forest are proving almost unbeatable at home and survived a late sending off to dispose of Ipswich Town at The City Ground courtesy of a brace from in-form striker David Johnson.
Johnson grabbed his 19th of the season after just five minutes to put Paul Hart's side ahead and the former Ipswich man then buried his old side by notching his 20th of the season just after the hour to keep Forest up with the leaders.
David Prutton was sent off late on and Gareth Williams's own goal made it 2-1 to the hosts but they held on for the points.
Reading stay in contention at the top as they piled more misery on bottom side Brighton with John Salako's 22nd minute strike earning Alan Pardew's man a 1-0 win at The Withdean.
Wolves missed the chance to keep pace with the leaders after being held to a goalless draw at Rotherham.
Norwich grabbed a late win at home to Derby with Malky Mackay's 82nd minute header proving to be the difference at Carrow Road, to keep them in touch with the leaders.
Wimbledon maintained their impressive form at the deserted Selhurst Park by inflicting a 3-0 defeat on hapless Sheffield Wednesday.
Lionel Morgan benefited from Wednesday's ill-discipline when a free kick was advanced ten yards to put him close enough to fire The Dons ahead three minutes before the break.
Chris Turner's nightmare start to his Hillsborough career then got even worse when Leigh Bromby was dismissed for a professional foul on Joely McAnuff shortly before the hour mark.
Prolific David Connolly then added insult to injury when he notched his 11th goal in eight games in the 63rd minute, and Neil Shipperley added a late goal to make it 3-0.
On loan Middlebrough striker Dean Windass grabbed his second goal in two games to give The Blades the lead at home to Crystal Palace just before half time.
Finnish international Aki Riihilahti hit back for The Eagles after 69 minute but Wayne Allison popped up in the final minute to earn a 2-1 win for neil Warnock's men at Bramall Lane.
Watford grabbed a welcome win at Vicarage Road with a 2-1 win over ten-man Burnley.
Icelandic star Heidar Helguson opened the scoring five minutes from half time and Tommy Smith doubled their lead from the penaly spot following Mark McGregor's dismissal.
Gareth Taylor replied for the ten-man Clarets but it was not enough to gain a point.
Preston North End left it late to claim a 2-1 away win at Coventry City as Eddie Lewis notched the winner two minutes from time.
Richard Cresswell gave North End the lead after just seven minutes but Calum Davenport levelled for Gary McAllister's side on 80 minutes before American Lewis grabbed the winner for Craig Brown's side at Highfield Road.
Millwall left it late to seal a 1-0 win against lowly Bradford as The Bantams had Wayne Jacobs sent off on the hour, with substitute Neil Harris got the winner eight minutes from time.
Tony Pulis came away from his return to Gillingham with a point as his Stoke City side came from behind to earn a 1-1 draw when Clive Clarke cancelled out Paul Shaw's opener.
Match summaries:
Brighton & Hove Albion v Reading
Coventry City v Preston North End
Gillingham v Stoke City
Grimsby Town v Leicester City
Millwall v Bradford City
Norwich City v Derby County
Nottingham Forest v Ipswich Town
Portsmouth v Walsall
Rotherham United v Wolves
Sheffield United v Crystal Palace
Watford v Burnley
Wimbledon v Sheffield Wednesday
