Derby took the first step towards easing the pain of their play-off final defeat with a 1-0 victory over Championship newcomers Rotherha
Rotherham live updates
Goals from Tom Lawrence and Alex Revell earned Rotherham their first win in 10 matches to pile the misery on fellow strugglers Wigan in the Sky Bet Championship.
The 2-1 result now leaves Wigan - one of the pre-season favourites for promotion - six points adrift of safety, extending their miserable run to one win in 17 matches.
Lawrence scored the opener for Steve Evans' Rotherham after a dreadful mistake by Andrew Taylor.
Wigan levelled just after the hour mark when Ben Watson headed home James McClean's corner.
But the visitors picked themselves off the canvas and regained the lead within a minute, Revell heading past Scott Carson from close range.
Rotherham chairman Tony Stewart has backed his manager Steve Evans to take the Millers to the Premier League after handing him a new three-year contract.
The South Yorkshire club were struggling to get out of League Two before Evans' arrival from Crawley in April 2012, but the Scot has transformed their fortunes, leading them to back-to-back promotions in his first two full seasons at the helm.
The latest rise was achieved by beating Leyton Orient on penalties in the League One play-off final at Wembley on Sunday and Stewart has moved quickly to tie his man down until the summer of 2017.
Rotherham came from two goals down to win promotion to the Championship after a dramatic penalty shoot-out at Wembley.
Leyton Orient appeared to be in control when Moses Odubajo and Dean Cox struck in the space of five minutes to give the O's a 2-0 lead at the interval.
But Alex Revell pulled a goal back for Rotherham with a tap-in from a free-kick, and the 30 year-old levelled matters in stunning fashion five minutes later, volleying over Jamie Jones from outside the area.
After tiring half hour of extra-time, Rotherham's Lee Frecklington saw his spot kick brilliantly parried by Jones, while Adam Collin denied Orient's Mathieu Baudry.
Substitute Chris Dagnell, Orient's fifth penalty taker, needed to score to keep the O's alive, but his shot was saved by Collin.
The O's team sheet http://t.co/RdNbXdP0a5
Today's team: Collin, Tavernier, Morgan, Arnason, Skarz, Agard, Smallwood, Frecklington, Pringle, Revell, Thomas. http://t.co/kR89GE75OA
Subs for the Millers: Shearer, Brindley, Davis, O'Connor, Milsom, Vuckic, Hitchcock.