DERBY County's 12-match unbeaten run was ended by a 2-1 defeat to Wigan Athletic at the iPro Stadium.
John Eustace put the Rams ahead on the stroke of half-time, moments after Jack Butland had saved James Tavernier's penalty.
But the Latics hit back after the break with two goals from substitute James McClean as Derby were beaten at home for the first time since March.
Despite the loss, Steve McClaren's men remain top of the Championship table on goal difference.
The Rams found chances hard to come by in the opening period.
Wigan might have had a penalty after 19 minutes when Callum McManaman went down under a rash challenge from Cyrus Christie.
But referee Bobby Madley gave a goal kick, then booked McManaman and Rams skipper Richard Keogh following the tussle that ensued.
Marc-Antoine Fortune blasted a shot from a tight angle across goal, while Adam Forshaw's long-range effort cleared the bar.
After 31 minutes, Roger Espinoza played in McManaman but his low shot was superbly kept out by the legs of Butland.
Derby finally mustered their first shot after 39 minutes, Jordon Ibe feeding Johnny Russell, whose first-time curler from 20 yards went narrowly wide.
In the 44th minute, Ibe cut in from the left but fired wide from a difficult angle.
Moments later, Wigan were awarded a penalty, for a disputed handball against Eustace.
Tavernier stepped up but Butland saved brilliantly, diving full stretch to his right.
That lifted the home crowd and Derby took an unlikely lead in the third minute of added time.
Russell's free kick from the right was attacked by Zak Whitbread and volleyed home by Eustace from close range.
McClaren still made a double change at the break, bringing on the fit-again Simon Dawkins and Jeff Hendrick for Ibe and Will Hughes.
Dawkins almost made an immediate impact, firing a low shot inches wide from 20 yards in the 47th minute.
Hendrick also went close, in the 56th minute - his first-time effort was parried by Scott Carson and cleared before Craig Bryson could pounce on the loose ball.
After 67 minutes, Chris Martin teed up Bryson, whose side-foot shot was helped on by Hendrick, only for Rob Kiernan to make a crucial block.
Two minutes later, Wigan were level.
Zak Whitbread half-blocked Roger Espinoza's cross from the right but the ball found its way into the middle and substitute McClean arrived just ahead of Cyrus Christie to beat Butland from six yards.
Tavernier might have made amends for his penalty miss but saw his 20-yard strike fly just wide.
McClaren made an attacking final change, bringing on Leon Best for Eustace, but it was Wigan who got the next goal.
Adam ForshaW's shot was beaten out by Butland and Fortune's follow-up was well blocked.
However, the ball broke for McClean, who just did enough to send the ball into the unguarded net.
Derby's best chance of an equaliser came in the 90th minute when Martin curled a free kick inches wide from the edge of the box.
DERBY COUNTY: Butland, Christie, Keogh, Whitbread, Forsyth, Eustace (Best, 80), Hughes (Hendrick, 46), Bryson, Russell, Ibe (Dawkins, 46), Martin. Other subs: Roos (gk), Buxton, Mascarell, Calero.
WIGAN ATHLETIC: Carson, Tavernier, Barnett, Kiernan (Kvist, 85), Figueroa, Huws (Maloney, 70), Cowie, Forshaw, Espinoza, McManaman (McClean, 62), Fortune. Other subs: Al Habsi (gk), Riera, Waghorn, Delort.
REFEREE: R Madley (West Yorkshire).
ATTENDANCE: 28,824.
