Cook fettuccine to desired doneness as directed on package. Drain, keep warm.
Meanwhile, cook bacon in medium skillet until crisp; remove bacon and drain on paper towels. Reserve 1 Tbsp. Drippings in skillet. Add onion; cook until crisp-tender. Crumble bacon; add to onion with tomato and basil. Cook just until heated. Immediately toss with cooked fettuccine. 4 side dish servings; 2 main dish servings.