Craig Reid's second-half penalty helped Aldershot defeat 10-man Barnet in a battle of the League Two strugglers.
Barnet, without player-manager Edgar Davids because of injury, should have been ahead at half-time but Barry Fuller's close-range effort flew wide.
But within four minutes of the restart they were one down - and a man short.
Reid netted from the spot after Sonny Bradley's shot was handled before Jon Nurse was dismissed for a dangerous tackle on Dani Lopez.
An offside flag denied Jake Hyde an equaliser, leaving Barnet third from bottom, just a point above the drop zone.
The Shots' first victory in three matches moves them up to 20th.
VIEW FROM THE DRESSING ROOM
Aldershot Town manager Dean Holdsworth told BBC Surrey:
"A massive three points for us and a real confidence booster. We need another 21 of those.
"We knew they would have spells in the game and we weathered that.
"We want to play as much as we can but the conditions don't always allow that. We had to be patient and got our goal and we deserved it."