Samoa -Fast Pitch - James Irvin would say yes.
He one punched KO'd Irvin? No. He doesn't possess that kind of power. He possesses laser accuracy with very good power and then swarms for a ref stoppage.
'Swarms'? That makes it sound like he swings wildly until the ref pulls him off. One of the things I find most impressive is his accuracy when punching a downed opponent. Irvin was covering up and he still managed to land cleanly.