Brentford had goalkeeper Simon Moore to thank for their victory over Carlisle after his penalty save from Joe Garner.
The Bees led after 20 minutes when Jonathan Douglas volleyed home Harry Forrester's corner but six minutes later Garner took advantage of Harlee Dean's slip to level.
Paul Hayes scored the winner with a mis-hit shot after reacting quickly.
United had a chance to level when Tony Craig was ruled to have fouled David Symington but Moore was the Bees' hero.
VIEW FROM THE DRESSING ROOM
Brentford boss Uwe Rosler told BBC London 94.9:
"I was very pleased with the direction of the players in the second half.
"I wasn't sure after we played so poorly in the first half how it would affect us. The players responded very well and totally changed the character of the game.
"They did exactly what I asked them to do."
Brentford 21 Moore 05 Craig 06 Dean Booked 14 Logan 24 Bidwell 04 Forshaw (Saunders - 87' ) 08 Douglas Booked 20 Diagouraga 09 Donaldson Booked 19 Forrester (Barron - 83' ) 23 Hayes Substitutes 01 Lee 03 Barron 31 Pierre 07 Saunders 15 Dallas 27 Oyeleke 30 German Carlisle United 01 Collin 02 Simek 06 Murphy 15 Edwards 04 McGovern (Symington - 67' ) 08 Noble (Welsh - 81' ) 16 Potts 21 Berrett 24 Chantler 22 Garner 27 Higginbotham (Beck - 81' ) Substitutes 20 Gillespie 23 McGinty 07 Welsh 18 Todd 19 Symington 11 Cadamarteri 17 Beck
Ref: Andy Davies