A dour, goalless game at Mansfield produced the one point Fulham needed to move 13 points clear of fourth-placed Swansea, who have only four games to play.
Wigan held on to the lead Pat McGibbon gave them just before the interval for a 1-0 win at home to Colchester that launched their celebrations, and took them above Fulham at the top.
Carlisle needed to win at Darlington to guarantee their step up but, despite Rory Delap giving them an eighth-minute lead, they lost 2-1 to second-half goals from Darren Roberts and Michael Oliver. It is the second time in four days that Carlisle have been forced to put the champagne on ice, following their home defeat by Fulham on Saturday.
Rotherham are relegated to the Third Division after losing 1-0 at Wrexham to Karl Connolly's 48th-minute goal.
The Second Division leaders, Bury, continued their march towards promotion with a 2-1 home win against Walsall, but second-placed Luton were held 0-0 at home by struggling Wycombe. Bury, unbeaten at Gigg Lane this season, recorded their 15th win in 20 home League games courtesy of Tony Battersby's 74th-minute goal.
They could swap places with their near-neighbours, Oldham, who are still in the First Division relegation zone despite twice coming from behind, with a penalty by Lee Richardson and a Paul Reid free-kick, for a 2-2 draw at home to Birmingham.Reuse content