Former undisputed junior welterweight world champion Josh Taylor was blown away by Saturday's performance from Oleksandr Uysk.
In 2018, Usyk became the undisputed world champion in the cruiserweight division when he easily outboxed Murat Gassiev over twelve rounds in the final bout of the first season of the World Boxing Super Series tournament.
He moved up to the heavyweight division a year later.
Last weekend, before a huge crowd at Tottenham Hotspur Stadium, Usyk outboxed a heavily favored Anthony Joshua over twelve rounds to capture the IBF, IBO, WBA, WBO heavyweight titles.
Usyk became one of the few fighters in boxing history to move up from the cruiserweight division to capture a world title at heavyweight.
"It was an absolutely brilliant performance. Usyk outclassed Joshua, out-maneuvered him, out-boxed him and sometimes even out-fought him. He was close to getting the stoppage in the 12th round. It was a massive statement. He is a brilliant fighter," Taylor said to Sky Sports.
"I said before the fight that I wouldn't be surprised if Usyk got the win and got the stoppage, and he almost did, because he's got the talent and the skill. He has proved that he belongs up there with the best of them."
Former cruiserweight world champion Johnny Nelson, like others have said, would like to see Joshua get more physical in the likely 2022 rematch.
"Joshua has surprised us before. When he lost to Ruiz Jr everybody said: 'That's it, he's done, he is totally exposed'. He has to devise a completely different game-plan here. He tried to out-box a very good boxer. Now he has to out-bash a very good boxer," Nelson said.
"I'm trying to work out what other option he has. He needs to start letting go of the right hand. Let it go like it's a jab. There needs to be fluidity in his work in both hands. He will look back at the successes and what he neglected to do. He needs to be smart. Because he gave this guy too much space."