Place chicken between 2 sheets of heavy-duty plastic wrap; flatten to 1/2-inch thickness using a meat mallet or rolling pin. Rub evenly with olive oil, and sprinkle evenly with chili powder, garlic salt, and paprika.
Grill chicken, covered with grill lid, over medium-high heat (350° to 400°) 4 minutes on each side or until done. Serve with Pineapple Salsa. Garnish, if desired.