Usyk in tears for late father after historic heavyweight win
The 37-year-old Ukrainian won a split decision against Britain's Tyson Fury in Riyadh in the first heavyweight unification fight since 1999.
The former European and world amateur champion, Olympic gold medallist and undisputed cruiserweight champ - still undefeated as a professional - now adds the ultimate boxing crown.
Afterwards Usyk, who needed four stitches to a cut above his right eye, and who was headed to hospital for a scan of his jaw, remembered his father, who died shortly after his Olympic victory in 2012.
"I miss my father," he said, wiping his tears with his T-shirt. "I know he's here."
Usyk has missed children's birthdays and even the birth of his daughter during his eight-month camp for the Fury fight, originally scheduled for February before the Briton suffered a cut in training.
His promoter Alex Krassyuk believed that Usyk was denied a knock-out victory when the referee stepped in as Fury looked about to hit the deck in round nine.
"I believe the referee saved Tyson from a knock-out and stole the ninth-round knock-out, which should have happened," Krassyuk said.
But Usyk said: "No knock-out, no problem."
"I don't think about it because we had a win."