Dan Sweeney's first Barnet goal secures a fourth win on the bounce for the bees as they see out the game with 10-men.
An early chance for Jack Taylor had to be saved by David Gregory before David Tutonda almost caught out the Bromley 'keeper as his cross from the left wing almost sailed into the goal.
Cheye Alexander had an effort blocked after he cut inside from the right while at the other end, Craig Robson had to make a vital interception to cut out the danger created by Junior Ogedi-Uzokwe.
With 13 minutes on the clock, Dan Sweeney surged at the Bromley goal before firing a low shot which Gregory managed to deal with. Two minutes later, David Tutonda was shown a yellow card after he went down under pressure in the penalty area, adjudged to have dived.
The Bees took the lead in the 21st minute from a corner created by Jack Barham which looked like a lost cause. The corner routine looked straight from the training ground, the ball came out to Wes Fonguck who delivered to the far post where Robson knocked it back across for Sweeney to head home from 6-yards, his first goal in a Barnet shirt.
Shortly before the half-hour mark, Jack Taylor's header from Barham's cross had to be dealt with before Bromley had their best chance of the game when Ogedi-Uzokwe was given just enough time and space to unleash a powerful effort from all of 35 yards. Cousins dived to his right and was grateful to see the ball cannon back off of his post.
Sweeney, then Robson and then Alexander all threw their bodies into the path of three Bromley efforts at goal.
Before the break, Tutonda toyed with the Bromley defence, beating one man after several stepovers. He set up Wes Fonguck who was unfortunate to see his low effort strike the upright.
After the break, Barnet looked to extend their advantage, Barham having a shot deflected wide before Charlee Adams' headed over Elliott Johnson's corner.
Taylor managed to find space at the far post from Tutonda's cross but put his first-time effort wide of the target while at the other end, George Porter's volley was saved by Cousins.
On 62 minutes, Jack Barham hit a sensational volley at goal from the edge of the box, the ball struck the underside of the bar and despite the strikers' appeals, the officials decided that the ball hadn't crossed the line.
Barham had another chance a few moments later, cutting back onto his right foot but curling it just over before Harrison played him through again but Gregory saved his effort at the near post.
With 4 minutes of the 90 left to play, Barnet were reduced to 10 men. David Tutonda picked up his second booking of the match when he went in for a 50/50.
Despite the man advantage, Bromley never really troubled Cousins and it would be Barnet who would see out the match, pick up all three points and secure their fourth win in succession.
Barnet - Cousins, Alexander, Johnson, Robson, Adams, Harrison, J. Taylor, Fonguck (Payne 88), Tutonda, Sweeney, Barham (Walker 90).
Unused - Azaze, Sparkes, Mason-Clark
Attendance - 1,568 (305 Barnet)
Referee - Carl Brook