1. Prepare grill.
2. Combine first 3 ingredients in a shallow dish; stir well. Add fish, and let stand 5 minutes.
3. While fish marinates, combine peach slices and next 3 ingredients in a small bowl; stir well. Set aside.
4. Coat grill rack with cooking spray; place on grill over medium-hot coals (350° to 400°). Remove fish from marinade, discarding marinade. Place fish on rack or in a grill basket coated with cooking spray; grill fish, uncovered, 3 to 5 minutes on each side or until fish flakes easily when tested with a fork. Remove fish from grill, and top with peach mixture.