Daniel Cormier added the UFC heavyweight championship to his light heavyweight title after he stopped Stipe Miocic in dramatic fashion during the first round of their UFC 226 superfight.
Cormier (21-1-1NC) flattened the UFC's long-reigning heavyweight champ with a right uppercut out of a clinch.
He finished Miocic (18-3) on the ground with 27 seconds left in the round by landing several shots before the referee stepped in.
Cormier became the second fighter in UFC history to hold two championship belts simultaneously.
Conor McGregor was the UFC's featherweight champ in 2016 when he took the lightweight title from Eddie Alvarez.
The 39-year-old Cormier has never lost to anyone except Jon Jones, and his five5-inch height disadvantage against Miocic was no problem.