MILWAUKEE (CBS 58) -- Milwaukee native and famed martial arts instructor Duke Roufus has died. 

His longtime business partner of 29 years, Scott Joffe, announced the news on Facebook, saying he died peacefully in his sleep. 

Roufus was the lead coach at Roufusport MMA Academy in West Allis, where many MMA greats began their career. He was trainer to UFC and world MMA champions like Anthony and Sergio Pettis, Ben Askren, Tyron Woodley and more. 

He also trained WWE Superstar CM Punk during his run. 

Duke himself was a four-time kickboxing World Champion and is now considered one of the top striking coaches and MMA trainers, according to Roufusport's website. 

He was 55 years old.