In a medium sized bowl, combine the Italian salad dressing, dried thyme, Italian seasoning, lemon juice, and garlic cloves. Stir to combine.
Reserve 1/3 cup of the marinade (to be used for basting later).
Transfer the mixture to a large Ziploc bag. Add the chicken. Close the bag, and place in the fridge to marinate for 3-5 hours, or overnight.
Pull the chicken out of the fridge. Let sit at room temperature for 15 minutes. Remove the chicken from the marinade and discard the marinade.
Heat a grill to 350°F-400°F. Place the chicken breasts on the grill. **Cook the first side for 5 minutes. Flip and immediately thoroughly baste each chicken breast with the 1/3 cup of reserved marinade.
Close the grill lid and cook for an additional 5-6 minutes or until inside temperature reaches 155°F. *
Remove from the grill and place the meat on a plate, tent with foil to keep the meat warm. Let rest for 5 minutes before serving.