Australian Luke Wilkshire returned from the Olympics to help fire City to their first league win of the campaign.
He grabbed two goals as did Scott Murray who was dropped on Saturday by his best friend, player-manager Brian Tinnion.
Murray was best man at Tinnion's wedding in the summer and was made club captain.
But he has been rebuked by his new boss for a poor start to the season.
He responded with some devastating bursts down the right and was soon in action when he set up the first goal after winning a corner.
It was played short by Wilkshire who took a return from Christian Roberts before hammering a low drive inside the far post.
With more steadiness in front of goal Murray might have finished with two goals of his own before the break but had to wait until the second half to get on the scoresheet.
Brentford, who made three changes after the 3-0 home win on Saturday, failed utterly to get anyone in behind the home defence.
Their best chance of a goal came early in the second half when Steve Phillips, after a mix-up with his centre back Tony Butler, was stranded well off his line.
Deon Burton tried a long shot towards the empty net but it was off target.
Brentford's best hopes centered on the fight for supremacy between Isaiah Rankin and Butler but the City player came out on top.
Murray had more impact as the game went on and after a superb pass from Tinnion he went past Andrew Frampton before delivering a low shot into the far corner.
Brentford got back in to the game briefly when Kevin O'Connor got on the end of a long cross from Burton before placing a header out of the keeper's reach.
But City strolled to victory with Wilkshire and Murray each claiming another goal before the final whistle.