Place balsamic vinegar, olive oil, Worcestershire, honey, dijon, lemon juice, lemon zest, garlic, red pepper flakes, salt, and pepper into a medium bowl.
Use a whisk to mix everything together until combined.
Transfer grilled chicken marinade into a large baking dish or gallon-size bag and then add chicken. Submerge the chicken into the marinade and make sure it's covered in marinade.
Place into the fridge to marinate for 12-18 hours for best results (no less than 2 hours).