Sheffield United striker Michael Higdon was sent off along with Chesterfield goalkeeper Tommy Lee in a feisty derby at Chesterfield.
The Blades lost out in a five-goal contest which was played out to a packed Proact Stadium.
The visitors included new signing Paddy McCarthy at centre-half - 24 hours after signing on loan from Crystal Palace - as Ryan Flynn also started.
Captain Michael Doyle was first in the book after eight minutes for a foul, with a derby atmosphere in the Proact Stadium.
Craig Alcock had to come with a goal-saving tackle to deny Daniel Johnson as the Spireites played some neat attacking football.
The Blades had the ball in the net at the other end, but the linesman’s flag was up for offside.
The hosts took the lead with a screaming effort on 25 minutes. Great control from Johnson created space, and when the ball was rolled back to Jimmy Ryan he fired hom from 30 yards.
And it got worse for United three minutes later when Michael Higdon was shown a straight red card for a foul on Daniel Jones on the halfway line.
The numerical advantaged was cancelled out 12 minutes later, as goalkeeper Tommy Lee was sent off for bringing down Ryan Flynn on the edge of the penalty area.
But it was Chesterfield who doubled the goals tally, when Gary Roberts kept his cool one-on-one with Mark Howard, before rolling the ball inside the goalkeeper’s left-hand post.
Nigel Clough brought on Marc McNulty and Jamal Campbell-Ryce after the break to try and get into the game.
But it was the prolific Eoin Doyle made it 3-0 with 20 minutes remaining, tapping home after the impressive Johnson’s shot was deflected into his path.
United were gifted a goal back on 79 minutes.
Young substitute goalkeeper Myles Wright made a huge error in failing to pick up a routine shot and the ball bounced out invitingly for Marc McNulty to tap home into an unguarded net.
And Neill Collins headed home in four minutes of stoppage time, but they could not snatch an equaliser.