Barnsley reached the Sky Bet League One play-offs after a thrilling demolition of champions-elect Wigan at a stunned DW Stadium.
The Reds were heroic as they rallied from an early goal behind to thump Gary Caldwell’s Championship-bound side.
Paul Heckinggbottom’s men got off to a disappointing start, conceding after just 10 minutes.
Yanic Wildschut crossed in superbly from the left for hot-shot Will Grigg, who smashed a shot past Adam Davies from six yards.
Chris McCann almost doubled the lead for the hosts, before the Reds responded with Adam Hammill firing an effort straight at goalkeeper Lee Nicholls.
The Reds evened it up from the penalty spot in the 33rd minute.
Ashley Fletcher was tripped in the box by Stephen Warnock, leaving Sam Winnall to step up and beat Nicholls easily with a coolly-taken penalty.
Winnall did it again a minute before half-time, completing the first period turnaround as he tucked home to make it 2-1 to the Reds after Lloyd Isgrove’s shot had been parried by Nicholls.
The Reds stretched their lead in the 56th minute. This time Fletcher teed up Conor Hourihane, who fired into the corner of the Wigan net via a slight deflection.
When Josh Brownhill curled home a superb 25-yard free-kick with 16 minutes to go, the Reds were most definitely on their way to the play-offs.
Wigan (4-3-3): Nicholls; Daniels, Morgan, Pearce, Warnock; Power, Perkins, McCann; Jacobs, Grigg, Wildschut.
Subs: Jaaskelainen, Morsy, McAleny, Barnett, Colclough, Vukic, Wabara.
Barnsley (4-4-2): Davies; Scowen, Roberts, Mawson, G Williams; Isgrove, Brownhill, Hourihane, Hammill; Winnall, Fletcher.
Subs: White, Townsend, Toney, Nyatanga, McCourt, Tuton, Chapman.
Referee: Tony Harrington (Cleveland).