Leicester now have 44 points, giving them a four-point cushion to the third-placed MK Dons.
The Dons had started Saturday in second place after beating Brighton on Friday night, but Millwall replaced them in the final automatic promotion place thanks to a 2-1 victory at Walsall.
Leicester had to come from a goal down at Carlisle United, after Danny Graham had put the home side ahead in the 27th minute.
Andy King levelled the scores in the 59th minute lashing in a fierce shot from just outside the box. Ten minutes later Leicester took the lead when Bruno Berner forced the ball home following a corner.
Neil Harris levelled Teddy Sheringham's goalscoring record for Millwall when he put them ahead against Walsall, his 111th strike for the club.
Alex Nicholls levelled for the Saddlers, but Andy Frampton 's late header ensured all three points for the London side.
Lee Hughes rescued Oldham Athletic as the points were shared in a cracking meeting between two promotion contenders at Peterborough United.
It had looked all over for the Lactics as Posh went into a two-goal lead, through Aaron McLean's double, though his opener took a substantial deflection off Stefan Stam, but Hughes led the fightback with a goal in either half.
Leeds United slipped further off the pace after a 2-1 home defeat to relegation-threatened Colchester United.
David Prutton was sent off in the 66th minute and Mark Yeates struck the winner from the resultant free-kick.
The game was 1-1 at that point, as Colchester's Dean Hammond had levelled Robert Snodgrass' opener.
Ian Craney's goal after 49 minutes gave Huddersfield United a 1-0 win over Southend United at Roots Hall
Steve Guinan's first-half strike seemed to be setting Hereford United on the way to back-to-back wins for the first time this season, but Hartlepool United fought back to earn a deserved point after Dean Beckwith put through his own goal at Edgar Street.
Crewe Alexandra picked up their first win in 14 games thanks to Shaun Miller's strike in first-half stoppage time, which gave them a 1-0 home win over Swindon Town.
Cheltenham Town grabbed their first away win of the season, at Leyton Orient, thanks to a dramatic late strike from Ian Westlake.
The visitors had taken an early lead through Barry Hayles but Leyton Orient hit back with a penalty from Adam Boyd.
Stockport County beat Yeovil Town 4-2 at Huish Park, with three of the game's goals coming in a two-minute blitz at the end of the first-half.
Johnny Mullins scored twice for the Hatters, with Tommy Rowe and Carl Baker also netting. Nathan Smith and Paul Warne got Yeovil's goals.
Bristol Rovers were 2-0 victors over Tranmere Rovers at the Memorial Ground. Jo Kuffour and Chris Lines scored the goals.