Cook beans in boiling water 4 minutes or until crisp-tender. Rinse with cold water; drain and pat dry.
Cook bacon in a large nonstick skillet over medium-high heat until crisp. Remove bacon from pan, reserving 2 tablespoons drippings in pan; crumble bacon, and set aside. Add onions to drippings in pan; cook for 3 minutes, stirring occasionally. Add sugar and thyme; cook for 3 minutes or until onions are golden brown, stirring occasionally. Add the beans; cook 2 minutes or until thoroughly heated. Add vinegar, salt, and pepper; toss to coat. Stir in crumbled bacon just before serving.