Colby Covington beat Tyron Woodley by TKO before taking a call from United States president Donald Trump on Saturday.
Covington dominated Woodley in Las Vegas before a rib injury ended the fight in the fifth round.
The 32-year-old Covington attended a Trump rally last week and he received a call from the president after his win over Woodley.
"You are a great fighter man, I tell you, you make it so easy, I don't know how the hell you do that," Trump said in the call, which took place during Covington's interview on ESPN.
"Congratulations, I wanted to watch that fight tonight, I wanted to watch it, you were great."
Former interim welterweight champion Covington improved his record to 16-2 in his first fight since December last year, when he lost to Kamaru Usman for the title at UFC 245.