The judges awarded the fight and the belt to the Brazilian by scores of 49-46, 50-45 and 49-46 as previous champion Dominick Cruz continues to be sidelined after knee surgery.
Barao targeted Faber (pictured) with leg kicks right from the start of the fight, landing significant blows in each of the five-rounds as Faber struggled to block the shots and recover in time do any real damage of his own.
Knowing he needed to do more than just counter-strike, Faber finally attempted a takedown in the middle of the third round but could not land it and from there on in it was obvious Barao had the measure of his opponent.
“I knew he was good at keeping distance,” Faber said. “And he was able to keep his kicks from pretty far out. I knew he was tough.
“He hurt me pretty early with a knee to the rib and I think I might have a broken rib. It was nothing like (Jose) Aldo. Aldo really took my leg apart. I felt (Barao’s) kicks for sure but it wasn’t the same thing.”
UFC featherweight champ Aldo fought Faber in WEC 48 in April 2010 and easily defeated the American with a series of brutal leg kicks.
“I came very well prepared for everything," Barao, who extended his unbeaten run to 30 winis, said through his translator.
"I knew Faber was a great athlete and a great fighter. But I prepared myself very well, and that was the result. My coaches told me to keep [kicking the legs], but it was not only that."
In the co-main event, Tim Boetsch shocked Hector Lombard to end the Cuban’s 25-fight winning run.
Boetsch controlled the slow-paced bout as both fighter struggled to land any significant blows and did just enough to secure the decision. The first two judges scored the fight 29-28 for Boetsch, giving him victory, while a third gave Lombard the win by the same scoreline.
On the undercard, Ryan Jimmo wasted little time in getting the event underway when he secured a KO win over veteran Anthony Perosh in just seven seconds.
The 30-year-old Canadian, making his UFC debut, sent Australian Perosh to the canvas with an overhand right before landing just one more punch to secure the knockout.
Nick Ring survived a gruelling encounter as he took a unanimous judges’ decision to gain revenge of Court McGee.
The two first fought in the 11th season of The Ultimate Fighter with Ring emerging the victor, before he was forced out of the series with injury allowing McGee to go on and win the season.
But two years later and Ring again defeated McGee with all three of the judges calling the fight 29-28 in the Canadian’s favour.
Also on the undercard, Matt Riddle secured victory by submission over Chris Clements, trapping his opponent in an arm triangle choke, Chieck Kongo beat Shawn Johnson by unanimous decision and James Head snapped Brian Ebersole’s 11-fight winning streak with strong takedown defence and superior striking to earn a split decision victory.