Ukrainian boxer Oleksandr Usyk beat Russia’s Murat Gassiev by unanimous decision in Moscow to unify the cruiserweight division’s four titles.
Usyk, a former Olympic gold medalist, controlled the fight against the local favorite on July 21 to add Gassiev's WBA and IBF crowns to the WBC and WBO titles he already owns.
The 31-year-old Usyk said after the bout that he could move up to heavyweight to fight British boxer Tony Bellow.
"If he doesn't want to drop down [to cruiserweight], I'll happily go up to meet him," Usyk said. "I'll just eat extra pasta."
Despite the geopolitical tension between Ukraine and Russia, the two boxers embraced each other and exchanged warm smiles after the match in the Olympic Sports Complex.
"I had the best opponent in my professional career," said Gassiev, 24, whose record fell to 26-1, with 19 knockouts and one no contest.
"I do my best -- just today is Oleksandr's day," he added.
Usyk is now 15-0 with 11 knockouts.
Usyk was born in Crimea. He has said he was forced to leave the peninsula after Russia annexed it from Ukraine in 2014.
Russia has also aided separatists in eastern Ukraine in a war that has killed more than 10,300 people since 2014.
In another match, Norway’s Cecilia Braekhus, 36, remained the women's welterweight champion with a unanimous decision over Russia’s Inna Sagaydakovskaya, 33.
Braekhus’ record is 34-0 with nine knockouts, while Sagaydakovskaya fell to 7-1 and three knockouts.