Brimage, the former Ultimate Fighter season 14 contestant, showed vast improvement in his striking skill, battering Hettes with a stinging left hand en route to a unanimous decision win.
The judges scored it 29-28, 29-28, 29-28 for the southpaw.
The first two rounds were split. Brimage showed a diverse striking game in the opening frame, letting his hands go and routinely finding Hettes' chin throughout the duration of the five minutes. But Hettes turned the tide in the second, wobbling Brimage with a flying knee and then hunting the submission for an extended period.
Both men, however, were able to defend themselves when their adversary went for a finish.
It was Brimage's left hand and his ability to defend the takedown that likely won him the fight in the third. Hettes could never seem to stop him from landing the straight left, and it repeatedly found its home over the last five minutes. Hettes tried a pair of late takedowns, but Brimage easily fended him off to take the pivotal final round.
Brimage improved to 6-1 with his third straight octagon victory while Hettes' first career loss dropped him to 10-1.