4 boneless skinless chicken breast halves (4 ounces each)
In a small saucepan, combine the first nine ingredients; bring to a boil. Reduce heat; simmer, uncovered, for 10 minutes. Cool to room temperature.
Pour 1/2 cup marinade into a large resealable plastic bag; add chicken. Seal bag and turn to coat; refrigerate overnight. Transfer remaining marinade to a small bowl; cover and refrigerate for basting.
Coat grill rack with cooking spray before starting the grill. Drain and discard marinade. Grill chicken, covered, over medium heat for 4-7 minutes on each side or until a thermometer reads 170°, basting occasionally with reserved marinade.