The six-foot-four Dwyer, a 3-1 underdog from Kelowna, B.C., used his front kick to distract the Brazilian and then nailed him with a right hand. Macario toppled face first to the canvas before the referee stepped in three minutes 14 seconds into the fight.
The win was welcome news to Dwyer, who was at the other end of a beatdown in his UFC debut in Halifax in October when New Jersey-based Russian Albert (Einstein) Tumenov floored the Canadian with two resounding kicks to the head before the fight was stopped after 63 seconds.
"Not only for the first time fighting in a foreign country but you know coming off a tough loss against a really good opponent, I really had to show what I had tonight," Dwyer (8-2) said in the cage Sunday after his arm was raised. "I want to stay in the UFC."
Dwyer credited coach David Lea for suggesting the Superman punch. Macario kept lowering his hands in trying to defend the kick, opening him up.
The five-foot-11 Macario (8-3) has lost three of his four UFC fights including the final of the Brazilian version of "The Ultimate Fighter" TV series.
Antonio (Bigfoot) Silva faced former heavyweight champion Frank Mir in the main event at the Gigantinho Gymnasium on Sunday.