Wigan were poised for promotion to the Premiership after they raced into a 2-0 half-time lead against Reading at the JJB Stadium.
Lee McCulloch sidefooted in his 14th goal of the season in the 18th minute after Jason Roberts’ cutback from the byline found its way through to him.
It was 2-0 three minutes later as Roberts beat his marker with a clever dummy and rolled a low shot into the corner of the net.
The Latics had to equal or better Ipswich’s result away to Brighton and at half-time Joe Royle’s side were level at 1-1 on the south coast.
Shefki Kuqi gave Town a fourth-minute lead when he drilled a low shot home from Darren Bent’s pass but the Seagulls – needing a win to be certain of avoiding the drop – hit back six minutes later when Adam Virgo volleyed in.
At the bottom, Crewe were looking most likely to be the third side relegated as former Alex striker Dele Adebola’s close-range header gave Coventry a 1-0 lead.
The fact Gillingham were trailing 1-0 to already-relegated Nottingham Forest gave Dario Gradi’s men a glimmer of hope if they could recover against Coventry.
Forest centre-back Wes Morgan scored the goal as he turned in Kris Commons’ free-kick from close range.
West Ham and Derby were in pole position to secure the two available play-off places.
The Hammers led 1-0 thanks to Anton Ferdinand’s deflected strike away to Watford three minutes before the break while a quickly-taken free-kick by Inigo Idiakez gave Derby the edge at home to Preston, who are already guaranteed a play-off berth.
Sheffield United needed a big win and to hope West Ham and Derby lost to reach the play-offs, but were level at 2-2 against Wolves after 45 minutes at Molineux.
Joleon Lescott put Glenn Hoddle’s men ahead in the 12th minute as he reacted first when Seol Ki-Hyeon’s shot was parried by United goalkeeper Paddy Kenny.
The Blades responded within seconds and Alan Quinn’s rising drive was too good for Michael Oakes but Leon Clarke (23) restored Wolves’ advantage.
Once more the visitors hit back though as Andy Gray’s low shot in the 37th minute beat Oakes.
Cardiff led 1-0 at home to QPR thanks to Jobi McAnuff’s first goal since January from a Cameron Jerome cross.
The remainder of the day’s other matches, which included champions Sunderland at home to Stoke, were goalless at half-time.