Stockport gave new manager Sammy McIlroy his first win for two years - 1-0 at Brighton - as they turned the Second Division table upside down.
McIlory endured a long run without a victory when he was in charge of Northern Ireland.
He quit the Irish post to take over at Stockport, but his first two matches produced only one point.
However, Aaron Wilbraham brought a smile back to McIlroy's face with County's clincher 11 minutes from the end.
The tall teenager linked up with fellow trainee Andrew Welsh to condemn Brighton to a hat-trick of defeats under caretaker boss Bob Booker without scoring a goal.
Welsh escaped from Brighton full-back Kerry Mayo before crossing low for Wilbraham to slot in from close range.
It ended Brighton's sequence of five straight wins without conceding a goal at the Withdean Stadium. They have lost their way and the leadership of the Second Division since Steve Coppell left for Reading.
The only threat offered by Brighton in a dull first half was the aerial power of Guy Butters from corners.
Young striker Chris McPhee almost broke the deadlock in the 58th minute with a swivelling half volley which forced Stockport keeper James Spencer into a fine save.
Midfielder Richard Carpenter nearly rescued a point for Brighton in stoppage time with a shot which was deflected just wide.
McIlroy said: "It was a magnificent performance. It was the first Brighton home defeat in six months and we deserved it." "We battled, we unsettled them and we created a few chances in the second half. I am not surprised because we have got potential and the lads were keyed up for it." Booker, who pulled out of Brighton's managerial race before the match, said: "The players had done it in two games for me, then in the next two they did not give a good account of themselves. That was a reflection on me and I didn't want it to drag out." Brighton chairman Dick Knight has pledged to have his eighth manager in six years in place by the middle of next week.
There is a four way fight for the job involving former Millwall manager Mark McGhee, Torquay's head coach Leroy Rosenior, Oldham chief Iain Dowey an ex-Southampton boss Stuart Gray.