The striker slotted home Danny Green's right-wing cross from close range just after the hour-mark to cement the Addicks place at the top of League One.
But the Bees missed enough first-half chances to have sealed a home win, Clayton Donaldson heading over from eight yards and Gary Alexander seeing a low drive tipped wide by former Bees goalkeeper Ben Hamer.
The breakthrough came just after the hour after Brentford right-back Shaleum Logan was stretchered off with a neck injury after a clash with his own goalkeeper Richard Lee.
Brentford's best chance came on the half-hour when Niall McGinn flashed a shot against the far post and Toumani Diagourage sliced the rebound wide.
Lee made two saves late on as his side pressed for an equaliser, tipping efforts from Wright-Phillips and Yann Kermorgant wide, while Bees substitute Mike Grella saw an injury-time header blocked at point-blank range by Hamer as the home side's lack of firepower once again cost them at home.