UFC 173: Barão vs. Dillashaw was a mixed martial arts event held at the MGM Grand Garden Arena in Las Vegas, Nevada on May 24, 2014. A Bantamweight Championship bout between Renan Barão and Raphael Assunção was targeted as the event headliner. However, Assunção opted to decline the bout as a rib injury sustained in his last bout at UFC 170 had not healed enough to resume the proper training... see more