A Tresor Kandol brace and a sensational Gary Alexander strike earned Millwall a well-deserved 3-2 win over Bristol Rovers in an end-to-end encounter at The Den.
The Lions replaced MK Dons, who lost at home to the Iron, in second place.
Peterborough United recorded a 3-1 win over Stockport County at Edgley Park, although they were aided by two own goals from the Hatters. Craig Mackail-Smith scored the only goal for Posh that did not come off a home player.
Oldham Athletic were forced to settle for a disappointing 1-1 draw as 10-man Brighton and Hove Albion stood firm at Boundary Park. The Latics occupy the final play-off spot.
There was again no joy for Gary McAllister's Leeds United. Just seven days after their shock FA Cup defeat at Histon they went down to their fifth away reverse in League One, they lost 2-1 tot a defiant Tranmere Rovers.
Michael Collins' rebirth under Huddersfield Town caretaker boss Gerry Murphy continued as he struck a dramatic stoppage-time winner.
Town were heading for another home stalemate at home to Walsall before midfielder Collins pounced in the third minute of added time to seal a 2-1 victory.
Cheltenham Town ended a run of seven league games without a win by beating bottom club Crewe Alexandra at Whaddon Road. Central defender Drissa Diallo - a loan signing from MK Dons - struck from a corner three minutes into the second half.
Carlisle United captain Paul Thirlwell spared teammate Peter Murphy's blushes to rescue a point in a 1-1 draw at Swindon Town, after Murphy had scored an horrific own goal.
Lowly Hereford United shocked hosts Colchester United by recording their first away league win of the season, thanks to two first-half goals.
Steve Guinan and Lionel Ainsworth scored for the Bulls, and although Jermaine Easter lashed home one strike the Us could not find an equaliser.
Leyton Orient stretched their unbeaten run to seven matches with a 1-1 draw at Northampton Town.
Neither team could find a way through some panic-stricken defending in perfect, if cold, conditions as Hartlepool United and Yeovil Town cancelled each other out at Victoria Park.