Place chicken breasts prepared pan. Bake for 15-20 minutes, or until chicken is no longer pink in the middle. Cut chicken into 1-inch cubes; set aside.
While chicken is baking, heat oil in large skillet over medium-high heat. Saute onion, garlic and zucchini. cook, stirring frequently, until vegetables are soft.
Add tomatoes and Italian seasoning; stirring occasionally. Reduce heat to medium-low. Cook at a gentle boil for at least 5-7 minutes.
Add cubed chicken to sauce; cook for 10 minutes.
While sauce is simmering, cook pasta according to package directions; drain.
Serve chicken-tomato mixture over pasta.