Cambridge United boss Colin Calderwood admitted Matt Preston’s red-card had been the game-changer in his side’s 4-0 win at Mansfield.
The game was deadlocked at 0-0 with Mansfield Town on top, until Preston was sent-off for a wild challenge on Luke Hannant on 49 minutes.
The visitors dominated from that point and wrapped up a miserable night for struggling Stags with late goals from Jack Roles, Sam Smith, George Maris and Reggie Lambe.
Calderwood said: “If ever there was a deciding factor in the game it was that red card. I did not think we did anything in the first half that warranted any praise.
“We stuck in the game and they missed their moments on counter attacks and long balls.
“They unsettled us at the back in the first half and we tried to get rid of the ball too quick and we did not have the control.
“You have to feel sorry for John Dempster and the situation he is in and getting beat 4-0 at home.
“Up until the tackle we would have been happy to have walked away with a clean sheet.
“We can play better and we did in the second half, but it took until ten men.
“Some of the stuff against 10 men was good, but we have got to be able to do that against 11 men as well.”