Combine undrained pineapple, lemon juice, oil, oregano and garlic powder in large shallow, non-metalic dish. Add chicken, turning to coat all sides. Cover and marinate 15 minutes in refrigerator.

Grill or broil chicken and pineapple, brushing occasionally with reserved marinade, 10-15 minutes on each side or until chicken is no longer pink in center and pineapple is golden brown. Discard any remaining marinade.