Pourmarinade over breasts. Cover with plastic wrap and marinate inrefrigerator,turning once or twice in marinade, for at least 2 hours,or up to 4 hours. Remove breasts from marinade, scraping any bitsclinging to chicken back into the shallow dish. Transfer all marinadeto small saucepan and bring to a boil; reserve. Lightly grease grillrack with cooking spray. Preheat grill. Place breasts on grill. Cookcovered with lid, basting frequently with marinade, until tender,approximately 5 to 6 minutes on each side.