Or cocky period. Murtzaliev after he beat Tszyu thought he was hot ****. Arrogant smile on his face, talking like he was a God. He lost his belt the very next fight. Danny Green after he beat Roy Jones. He was carrying on as if it were Roy Jones pre Tarver 2. Absolute flog. " When you beat a legend you become a legend " No you don't. He beat a past legend.
So... he got cocky in 2017, or was it in 2023, or maybe now after beating Jake Paul and Kristian Prenga back to back? The OP asked for after a particular win, your comment makes no sense. Joshua was cocky the moment he turned pro, he didn't suddenly get super confident after any particular win.
Got dropped all over the shop by a nobody the proceeded to spew a mike Tyson quote directed at Fury, ironically that mike Tyson rant was to Lennox Lewis who toyed with him in their bout but I'm sure AJ is too dim to realize that. Fury hit the nail on the head back in 2013, AJ is just a dumb fighter who gets told what to do by his manager Eddie hearn.
You could argue Ruiz got a bit cocky given he’d have likely flattened AJ in the rematch had he not spent the entire training camp eating
Hasim Rahman after he beat Lennox Lewis Tony Harrison after he beat Jermell Charlo George Kambosos after he beat Teofimo Lopez although one can argue that he was just playing the role to sell the Devin Haney fight (which I do believe)