Barao (32-1) defended his UFC bantamweight title for the first time on Saturday, earning a first-round TKO over Faber (30-6) just 3:42 into their title fight at UFC 169 at the Prudential Center.
It was an electric performance by Barao, partially marred by a premature stoppage that was uncharacteristic of referee Herb Dean.
Despite being dropped moments before, Faber was actually signaling a "thumbs up" as Dean moved in to stop the fight. The result is his sixth consecutive loss in a title fight.
"It's very frustrating," Faber said. "I'm one of the most durable guys in the world. You get caught with punches, man. He told me to do something, so I gave him a thumbs up. Herb is a great referee, but I wish I had more of a chance."
The final sequence began when Barao scored a hard knockdown on a straight right hand up the middle. Faber fell to his back, but eventually popped to his feet after defending the ensuing swarm of punches by Barao.
Barao stayed on him, though, staggering him with a left hook and then dropping him again moments later with the overhand right. Faber attempted to slow things by tying up Barao's right leg from a turtled position. Barao responded with punches to the side of the head, which Faber appeared to do a good job of blocking.
Dean, however, had seen enough and called a stop to the 135-pound contest. It marks just the third time Faber has been stopped in his career and first since a TKO loss to Mike Brown in June 2009.
Afterward, even Barao admitted he was somewhat surprised by the stoppage.
"A little bit," Barao said. "But I fought Urijah before. He's very tough and very resilient. I knew he was going to be a tough fight."