A late strike from Mallik Wilks gave Accrington a 2-1 victory at Chesterfield in Sky Bet League Two and increased the pressure on under-fire manager Gary Caldwell.
Billy Kee fired Accrington ahead after Bradley Barry was sent off and although Kristian Dennis equalised from the spot, Wilks won it eight minutes from time.
Accrington should have scored in the third minute when Sean McConville was unmarked six yards out but Joe Anyon made an excellent save.
Anyon pushed Kee's header onto the bar in the 33rd minute and a poor first half ended with the Chesterfield goalkeeper turning over a 20-yard McConville drive.
Chesterfield forced Aaron Chapman into action when he blocked a Dennis shot in the 52nd minute but the home side were reduced to 10 men when Barry was red-carded in the 63rd minute for a two footed tackle on Seamus Conneely.
Accrington took advantage five minutes later when Kee fired past Anyon at the back post only for Dennis to level from the spot in the 77th minute after Conneely pulled him down.
But Wilks fired in from the edge of the area in the 82nd minute to leave Caldwell's future in the balance with the Spireites in the relegation zone with just a single win this season.