Crewe were relegated from League One after losing 3-0 at local rivals Port Vale.
The Alex have flirted with relegation for the past few seasons but on Saturday their luck finally ran out. Louis Dodds scored with a shot from just inside the area after only three minutes and he netted his second goal of the game seven minutes from time, converting the rebound after JJ Hooper's effort was saved by Ben Garratt.
Substitute Hooper curled in a superb third goal in injury time to inflict a sixth straight defeat on Crewe.
At the other end of the table, Will Grigg's 23rd goal of the season saw Wigan extend their lead at the top with a 1-0 home win over Coventry. Grigg later saw a 66th-minute penalty saved by Reice Charles-Cook.
Long-time leaders Burton are now four points behind Latics after losing 1-0 at Scunthorpe, whose goal was scored by Neal Bishop on the hour.
Bradford are up to third in the standings after Billy Clarke's header gave them a 1-0 home win against Swindon.
Millwall are fourth after coming from behind to beat Shrewsbury 3-1 at The Den. Larnell Cole put the struggling Shrews ahead early on but goals from Ben Thompson, Steve Morison and a Lee Gregory penalty after goalkeeper Mark Halstead had been sent off earned a valuable three points for the Lions.
Gillingham are down to fifth spot following a goalless draw at Sheffield United while Walsall's dropped to sixth after losing 1-0 at Oldham, with Curtis Main's goal moving them out of the relegation zone.
Blackpool are back in the bottom four after a 1-0 home loss to second-bottom Colchester, whose late fight to beat the drop continued to gather pace with Chris Porter's strike.
Doncaster's dire run continued with a 1-0 defeat at Bury, Leon Clarke's goal for the Shakers leaving Rovers without a win in 15 league matches and staring relegation in the face.
Chesterfield boosted their survival hopes and dented Barnsley's play-off aspirations by winning 2-1 at Oakwell. Lee Novak put the Spireites ahead but Adam Hammill equalised and a red card for Jamal Campbell-Ryce seemed to give the hosts the advantage but Ollie Banks hit the winner for 10-man Chesterfield.
Conor McLaughlin's last-minute header kept Fleetwood's head above water in the relegation fight, earning his side a 2-2 draw with Southend. Bobby Grant put Fleetwood in front but goals from Adam Barrett and Jack Payne turned the game on its head before McLaughlin struck.
Goals from Joe Bunney and Nathaniel Mendez-Laing saw Rochdale win 2-1 at Peterborough, who replied through Michael Smith.