In a mixing bowl, combine olive oil, garlic powder, salt, and black pepper. Add the chicken breasts and coat well.

Preheat the grill to medium-high heat. Grill the chicken for about 6-7 minutes on each side or until fully cooked.

In a separate bowl, mix together diced mango, avocado, lime juice, and cilantro.

Once the chicken is cooked, remove from the grill and top with the mango avocado mixture before serving.