Seong Myeong-jun vs. Mammoth: Is there any chance Seong Myeong-jun can win?

Seong Myeong-jun, the "Incheon Boss" and former Jeonjin Gangster, recently defeated Kim Jung-woo—who caused controversy for knocking out a civilian—and has called out Mammoth. They are set to fight under Yacha Rules at Yacha Club in October, and I heard the fight money is 100 million KRW.
Since Hwang In-su, who is close to Seong Myeong-jun, along with several other professional fighters, have been sparring with him and saying he can definitely win, he seems extremely confident.
But even so, is it actually possible to beat Mammoth, who is the #1 ranked heavyweight in Black Combat?
Since it's Yacha Rules, which is more like a street fight rather than MMA, there might be variables, but wouldn't he just get beaten one-sidedly and KO'd?