Melt butter in a saucepan over medium heat. Stir barbeque sauce, Worcestershire sauce, and garlic powder together with the melted butter. Stir chicken into the sauce mixture to coat.
Place cover on saucepan and simmer until the chicken pieces are cooked through and no longer pink in the middle, 3 to 5 minutes. Remove cover and spoon sauce over chicken pieces; continue cooking until sauce thickens, about 4 minutes more.