In a small bowl, mix balsamic vinegar, olive oil, salt, and black pepper to create the marinade.
Place the chicken breast in a resealable plastic bag or shallow dish and pour the marinade over it. Let it marinate for at least 30 minutes in the refrigerator.
Preheat the grill to medium-high heat and lightly oil the grates.
Remove the chicken from the marinade and grill it for 6-7 minutes on each side, or until the internal temperature reaches 165°F (75°C).
During the last few minutes of grilling, place the slices of mozzarella on top of the chicken and allow it to melt.
Once cooked, remove the chicken from the grill and top it with a slice of tomato and fresh basil leaves.
Drizzle the balsamic glaze over the top before serving. Enjoy your Caprese Balsamic Grilled Chicken!