The winger, on loan from Newcastle, cracked home his second goal for Brighton 12 minutes from time from the edge of the area following a corner by Elliott Bennett.
Moments before Brentford keeper Ben Hamer had brilliantly denied substitute Glenn Murray as the Seagulls stepped up the pressure.
Brighton had a let off immediately after the break when Sam Wood's left-foot shot rebounded off the crossbar, while the Seagulls - now unbeaten in six league games - had a strong penalty appeal waved away when defender Craig Woodman appeared to pull back Ashley Barnes midway through the second half.
At the halfway point of the first half, keeper Hamer parried a volley from Bennett before Bees striker Nicky Forster headed wastefully wide at the far post following a cross from Myles Weston.
Hamer came to his side's rescue after 35 minutes by brilliantly turning a shot from Matt Sparrow around the post.