Process first 8 ingredients in a blender until smooth, stopping to scrape down sides.
Reserve ¼ cup lemon mixture, and chill.
Place chicken in a shallow dish or zip-top freezer bag; pour remaining lemon mixture over chicken.
Cover or seal, and chill 2 hours, turning chicken occasionally.
Remove chicken from marinade, discarding marinade.
Grill chicken, covered with grill lid, over medium-high heat (350° to 400°) for 3 to 5 minutes on each side or until done, basting chicken frequently with reserved ¼ cup lemon mixture.
Garnish, if desired.