Cook garlic in hot oil for 30 seconds in a small saucepan. Stir in tomatoes, salt, and black pepper. Bring to a boil and reduce heat. For 12 minutes, simmer uncovered. Stir in sage and sweet pepper. Simmer, uncovered, for about 5 minutes.
Meanwhile, cook pasta according to package except do not add salt or oil. Drain and return pasta to saucepan. Add sauce to pasta and toss.