Add the balsamic vinegar, soy sauce, olive oil, salt, Italian seasoning, and garlic powder to a gallon sized freezer ziploc bag. Seal and shake to combine.

Add in the chicken breasts. Seal bag and allow to marinade in the fridge anywhere from 30 minutes to 12 hours. 

Grill over medium high heat for about 4-5 minutes per side until it reaches an internal temperature of 165 degrees. Cooking time may vary based on the thickness of your chicken breasts. Cover with foil and allow to rest for about 5 minutes before serving. Serves 4.