The change in his job title made no difference to Brighton's poor run of form as Chesterfield claimed only their third victory out of nine in the league.
The visitors were the brighter team early on and almost took the lead in the 18th minute when Brighton defender Sam Rents allowed a harmless looking cross from Kevan Hurst to hit a post.
The visitors went in front two minutes later with a simple route one goal.
A long clearance by keeper Barry Roche was headed on by veteran striker Wayne Allison for his partner Caleb Folan to race between two Brighton defenders and slot home his seventh of the campaign.
Wilkins brought off Doug Loft soon afterwards and changed from 4-4-2 to 4-3-3 in an attempt to find a way back into the game.
Sam Williams, making his debut on a month's loan from Aston Villa, almost equalised just before half-time with a header from a cross by Gary Hart which looped narrowly wide.
Williams, 19, put the home side back on terms in the 54th minute with a well-placed header over Roche from a cross by Rents.
He had also headed a debut goal during a loan spell with Wrexham last season in a 2-0 victory and there seemed every prospect that Brighton would go on to win the game as well.
But Chesterfield had other ideas and regained the lead in the 74th minute. Midfielder Derek Niven exchanged passes with Folan and managed to steer a shot beyond Brighton keeper Wayne Henderson from inside the box.
Brighton had chances to equalise. Adam El-Abd headed wide from a corner by Dean Cox, Dean Hammond was denied by a fine tip-over by Roche and Alex Revell shot just too high from long range.
Chesterfield finished the match with ten men. The outstanding Folan had already been booked in the second half when he received a straight red card deep into stoppage time for swearing at a linesman.
The visitors were the brighter team early on and almost took the lead in the 18th minute when Brighton defender Sam Rents allowed a harmless looking cross from Kevan Hurst to hit a post.
The visitors went in front two minutes later with a simple route one goal.
A long clearance by keeper Barry Roche was headed on by veteran striker Wayne Allison for his partner Caleb Folan to race between two Brighton defenders and slot home his seventh of the campaign.
Wilkins brought off Doug Loft soon afterwards and changed from 4-4-2 to 4-3-3 in an attempt to find a way back into the game.
Sam Williams, making his debut on a month's loan from Aston Villa, almost equalised just before half-time with a header from a cross by Gary Hart which looped narrowly wide.
Williams, 19, put the home side back on terms in the 54th minute with a well-placed header over Roche from a cross by Rents.
He had also headed a debut goal during a loan spell with Wrexham last season in a 2-0 victory and there seemed every prospect that Brighton would go on to win the game as well.
But Chesterfield had other ideas and regained the lead in the 74th minute. Midfielder Derek Niven exchanged passes with Folan and managed to steer a shot beyond Brighton keeper Wayne Henderson from inside the box.
Brighton had chances to equalise. Adam El-Abd headed wide from a corner by Dean Cox, Dean Hammond was denied by a fine tip-over by Roche and Alex Revell shot just too high from long range.
Chesterfield finished the match with ten men. The outstanding Folan had already been booked in the second half when he received a straight red card deep into stoppage time for swearing at a linesman.