Watch HDToday. UFC 146: dos Santos vs. Mir was a mixed martial arts (MMA) pay-per-view event (PPV) promoted by the Ultimate Fighting Championship (UFC) on May 26, 2012 at the MGM Grand Garden Arena in Las Vegas, Nevada. The main card featured five MMA bouts which were shown on PPV, as well as seven preliminary bouts which were shown on FX, and Facebook. This was the first time in UFC history that the main card featured all heavyweight bouts.