A raucous Arena Riga cheered Briedis to the rafters during the bout which went the full 12-round distance but saw Usyk edge out Briedis on points according to the judges' scorecards.
Two judges scored the fight 115-113 in Usyk's favor while the third scored it a 114-114 draw.
Predictably the decision was not popular among the crowd, and many commentators said the decision could have gone either way.
Both fighters deserve immense credit for their commitment in a clean but brutal match-up that can rightly be regarded as a classic.
As a result of the victory, Usyk takes Briedis' world belt and advances to the next round of the World Boxing Super Series unification process.
In the post-match press conference both fighters praised each others' abilities and Briedis was even able to start by cracking a joke, saying he hoped everyone had enjoyed it. He also said "We need to do it again," signalling his desire for a rematch.
