Cook bacon in large skillet over medium heat until crisp; transfer to paper towels. Crumble bacon coarsely. Pour off all but 1 tablespoon drippings from skillet; reserve skillet.
Place lettuce and tomatoes in large serving bowl. Heat bacon drippings in skillet over medium heat. Add garlic, then mayonnaise and vinegar; whisk until blended, 30 to 40 seconds. Season dressing to taste with salt and pepper. Pour over lettuce and tomatoes and toss to coat. Sprinkle bacon over. Serve immediately.
