1Cook spaghetti as directed on package. Meanwhile, in 3-quart saucepan, cook beef and onion over medium heat, stirring occasionally, until beef is brown and onion is tender; drain.
2Stir in tomatoes, beans, tomato sauce, chili powder and salt. Cook uncovered over medium heat about 10 minutes, stirring occasionally, until as thick as you'd like.
3Drain spaghetti; divide among dinner plates. Top with beef mixture; sprinkle with cheese.