Mixed martial arts great Ken Shamrock is jumping into bare-knuckle boxing promotion.

Shamrock is starting a promotional company in the growing combat sport, he announced Tuesday.

Valor Bare Knuckle will hold its first fight card Sept. 21 at 4 Bears Casino in North Dakota, with plans for quick growth.

The long-dormant sport is on the rise in North America after Bare Knuckle FC staged the first sanctioned bare-knuckle bouts last year. The sport is already proving popular with pay-per-view audiences.

The 55-year-old Shamrock is an MMA pioneer who fought on the inaugural UFC 1 show in November 1993. Most competitors in that tournament fought without gloves.

Shamrock also competed in Japan and remained active as an MMA fighter until 2016.