Mairis Briedis earned a majority decision win over Yuniel Dorticos to claim the World Boxing Super Series final and IBF cruiserweight title.
Briedis received the Muhammad Ali Trophy after defeating Cuban Dorticos on Saturday, with two judges scoring the fight 117-111, while another had it 114-114 in Munich, Germany.
Dorticos (24-2) was the aggressor but Latvian Briedis – a former WBC and WBO champion – landed the more noticeable blows with a number of right uppercuts to dethrone the IBF holder.
"It feels like a dream," said Briedis (27-1), whose only professional defeat has come against Oleksandr Usyk in 2018.
Meanwhile, world champion Josh Taylor retained his WBA and IBF light-welterweight belts thanks to a first-round knockout of Apinun Khongsong.
Taylor's body shot sent the undefeated Thai fighter to the canvas in incredible fashion at York Hall in London.
"I felt it [the punch] sinking in straight away," Taylor told BT Sport. "I didn't know it had hurt him to that extent until I saw him on the floor.
"He [Khongsong] was the heaviest puncher I have ever been in with. I could feel the weight of his power. That switched me on to take my time and be patient.
"It was a great shot but I'd like to have shown what we've been working on in the gym. But you don't get paid overtime. I can go and get a pint and a pizza."