ALEX McLeish's start to life as Nottingham Forest manager took an embarrassing twist as League One strugglers Oldham sent them crashing out of the FA Cup.
Seven minutes of second half madness decided the tie in Oldham's favour, as the Reds went from being 1-0 ahead to finding themselves 3-1 down and reduced to ten men.
Two well taken goals from Robbie Simpson, the sending off of skipper Danny Collins for a professional foul, and a goal from Jose Baxter from the resulting free kick, all between the 54th and 61st minutes, put Paul Dickov's side into the fourth round.
Billy Sharp made it 3-2 deep into injury time but it was too late for any meaningful fightback and it left new manager McLeish looking for his first victory, three games into the role he took over from Sean O'Driscoll, who was surprisingly sacked on Boxing Day.
Radi Majewski, one of five players drafted back into the starting line-up by McLeish, was at the centre of things as Forest pinned Oldham back in their own penalty area in the first two minutes.
Majewski had one promising run into the box, before then feeding Simon Cox in space down the right, although the striker's cross was a disappointment, as he struggled to keep the ball in play.
Simon Gillett, Chris Cohen, Dexter Blackstock and Brendan Moloney were the other players brought into the team by the new manager, with Billy Sharp, Guy Moussi and Henri Lansbury dropping to the bench. Adlene Guedioura is on international duty with Algeria in the African Cup of Nations, while Daniel Ayala dropped out of the squad altogether.
There was also a change in formation for Forest, with Moloney playing as one of three central defenders, alongside Danny Collins and Greg Halford, with Chris Cohen and Dan Harding operating as wing-backs.
Andy Reid had a half chance on the edge of the box but dragged a powerful shot well wide of the target. Blackstock was twice halted by tight looking offside decisions, the second of which looked questionable and then had a shot charged down, following a neat turn just inside the box.
A foul on Blackstock then proved to be a decisive moment as, after Reid had delivered a teasing ball from the right, from the resulting free kick, Forest took a 13th minute lead.
With Simon Cox poised to pounced, Matt Smith's attempt to block ended with him prodding the ball into his own net at close range.
Majewski came close to adding a spectacular second with a swerving shot that had Dean Bouzanis scrambling across goal to cover as it bent narrowly the wrong side of the post.
Jean-Yves M'Voto produced an outstanding tackle to deny Blackstock a run on goal, after a driving run from Cox had split initially the Oldham defence. It seemed the Forest striker would break clear, but the Oldham man recovered to make a perfectly timed challenge.
Blackstock did break clear of the Oldham defence two minutes later, but Bouzanis kept his composure to make a good save and then regain his feet to close down the angle for a second time, denying the striker the room to shoot again or find a team mate.
Jose Baxter came mightily close to drawing Oldham level with an outstanding free kick, bent around the defensive wall, which skimmed the side netting as it fizzed just the wrong side of the post.
Forest were forced to make an early change as Reid limped off with an injury, following what appeared to be a clash of heads, with Lewis McGugan introduced a minute or two later after completing his warm up.
McGugan's ball to Cohen on the right kick started a promising attack, with Majewski's cross to the far post forcing the first of a flurry of corners, as Forest pressured for a second goal.
Smith did well to get in a header on the edge of the Forest penalty area, with Camp happy to see it loop onto the roof of the net. While Baxter also came close with a header, as Oldham finished the half in positive fashion.
Forest came close in the 50th minute when a Blackstock header, from a Cohen corner, took a deflection that took it a foot over the bar.
But it was to be Oldham who were to claw themselves level, courtesy of an impressive strike from Robbie Simpson. After Forest had lost possession just inside their own half, Oldham moved the ball quickly to the edge of the box, from where the midfielder arrowed a powerful shot beyond Camp and into the bottom corner of the net.
And, within seven minutes of that, things had completely fallen apart for Forest, who found themselves staring at an FA Cup exit.
Simpson made it 2-1 in the 58th minute, looping a header over Camp and into the corner of the net following a precise cross from Dean Furman towards the far post.
Camp denied the Oldham man a hat-trick when he blocked with his legs a minute later but, with Oldham on the rampage, Forest found themselves reduced to ten men when skipper Danny Collins was shown a red card in the 59th minute, after he had hauled down Smith on the edge of the box.
As if to rub salt in the wounds, Baxter lashed the ball into the bottom corner of the net as Oldham made the most of the free kick on the edge of the box.
In the space of seven nightmare minutes, Forest had gone from holding what had looked to be a comfortable lead, to being 3-1 down and with a numerical disadvantage.
There was a moment of controversy in the 66th minute when Cliff Byrne appeared to haul down Blackstock in the box, to deny the Forest man a chance on goal. But referee Roger East waved for play to continue.
Cohen's cross-shot almost carved out a goal for Forest, with Bouzanis saving well at his near post. But, generally, Oldham were defending solidly.
Keeper Bouzanis did spill a long throw from Halford, but there were no Forest players on hand to benefit.
And it was Camp who was forced into a spectacular save as Oldham pushed for a fourth goal, with M'Changama bending a shot across goal towards the far post, where Camp acrobatically pushed away.
McGugan had a shot deflected wide as Forest put the visitors under pressure, committing men forward. While Cox forced a save from the Oldham keeper with a low shot.
But Forest rarely looked like clawing their way back into the game, even after Sharp had netted in the 95th minute.
Forest: Camp, Moloney, Halford, Collins, Harding, Cohen, Majewski (Sharp 66), Gillett, Reid (McGugan 37), Cox, Blackstock. Subs: Evtimov, Lascelles, Moussi, Lansbury, Greening.
Oldham: Bouzanis, Grounds, M'Voto, Croft (Millar 93), Furman, Simpson (Taylor 82), Smith, Byrne, Baxter, M'Changama, Wabara. Subs: Cisak, Brown, Tarkowski, Winchester, Mellor.
Referee: Roger East, Wiltshire
Attendance: 11,293 (2,841 away)
