Heat oven to 375°F. Warm oil in large saucepan; cook garlic over medium-low 1 minute until fragrant. Add tomatoes, sauce, oregano, sauce salt, and pepper; gently simmer 15 minutes.
Meanwhile, boil ziti with tablespoon salt to 3 minutes short of package time. Drain without rinsing; fold into sauce.
Layer half pasta, half ricotta in dollops, and 3 oz mozzarella in deep 9-by-13-inch dish. Repeat remaining pasta and ricotta with another 3 oz mozzarella.
Top with remaining 4 oz mozzarella and Parmesan. Foil-cover; bake 25 minutes.
Uncover; bake 10 to 12 minutes until bubbling, center 165°F, and top patchily browned. Rest 10 minutes.