Renan Barao defends his bantamweight title for the fourth time on May 24 against TJ Dillashaw

With the original UFC 173 main event between Chris Weidman and Lyoto Machida moved to July's UFC 175 card due to an injury suffered by the middleweight champion, bantamweight titleholder Renan Barao has stepped up to headline the May 24 card at the MGM Grand Garden Arena in Las Vegas against top contender TJ Dillashaw.

Brazil's Barao (34-1, 1 NC) is the owner of a remarkable 35 fight unbeaten streak that includes 22 straight wins. Winner of the interim bantamweight crown in 2012, the 27-year-old was elevated to undisputed champion in January, and he didn't skip a beat, halting Dillashaw's teammate, Urijah Faber, in a single round at UFC 169 in February.

Looking to separate Barao from his championship belt will be the 28-year-old Dillashaw, an ultra-talented contender currently ranked fifth in the world at 135 pounds. A TUF 14 finalist, Dillashaw has won five of his last six bouts, most recently winning a unanimous decision over Mike Easton in January.

Japanese contender Takeya Mizugaki, who was originally scheduled to face Dillashaw at UFC 173, will now face hard-hitting Francisco Rivera.