A half-time tactical switch by Bees boss Mark Warburton saw the Londoners push up and pile the pressure on the visitors.
It paid off on the hour-mark when Clayton Donaldson broke the deadlock with a sizzling low drive from the edge of the box.
By the time George Saville's bobbling shot crept inside the upright in the 73rd minute, Bradford's resolve was broken.
Wayward finishing looked like sabotaging the Bees' bid to stay on the coat-tails of London rivals Orient, who could only manage a draw at Notts County.
Warburton said: "In the first half we were playing our football in the wrong areas, but after the break we stepped up 10 or 15 yards and it set the tone.
"The substitutes made an impact too and for 65 minutes we looked very strong."
He added: "Before this game people have been asking me how we were going to stop the rot.
"We've only lost one in 20 games! It's a very harsh world."
Warburton was delighted with the way his players pushed on after the break.
"We were a little too deep in the first half, but they will learn from that and recognise what they did well in the second half," he added.
Brentford dominated possession for long spells, but the Bantams' well-organised lines of defence ensured the scores stayed level.
After the opener, Brentford really should have punished the visitors, but squandered a string of chances to make the scoreline more impressive.
Donaldson headed Adam Forshaw's free-kick just past the post and should have made it a brace when he somehow skied Marcello Trotta's near-post cross over the bar from close range.
Jonathan Douglas headed against the bar and Saville forced a point-blank save from City goalkeeper Jon McLaughlin as Brentford piled on the second-half pressure.
City's only real effort of note came just before the break when Adam Reach beat three defenders only to fire over the bar.