Dean Windass and Marc Bridge-Wilkinson both scored twice in the first half as rampant Bradford put a dent in Brentford's play-off hopes.
Windass chipped keeper Stuart Nelson for the first before Bridge-Wilkinson converted Owen Morrison's pass.
Steven Schumacher set up Windass for the third and Bridge-Wilkinson hammered in the fourth right on half-time.
Bradford could have scored more before Jay Tabb hit Brentford's consolation after a one-two with Scott Fitzgerald.
Bradford: Ricketts, Holloway (Swift 86), Wetherall, Bower, Tierney, Muirhead, Schumacher (Bentham 88), Bridge-Wilkinson, Morrison (Emanuel 86), Cooke, Windass.
Subs Not Used: Henderson, Forrest.
Goals: Windass 6, Bridge-Wilkinson 23, Windass 37, Bridge-Wilkinson 45.
Brentford: Nelson, O'Connor, Turner, Sodje (Myers 45), Frampton, Rankin, Pratley, Gayle (Tabb 45), Salako, Burton (Harrold 45), Scott P Fitzgerald.
Subs Not Used: Bankole, Lawrence.
Booked: Scott P Fitzgerald, Frampton.
Goals: Tabb 79.
Ref: K Wright (Cambridgeshire).