The increasing popularity of store brands is resulting in greater cannibalization of national brands. Thus, national-brand manufacturers are trying their best to confront this trend. At the same time, however, many leading national-brand manufacturers have become involved in the store-brand production of their counterpart retailers. We construct a game-theory-based framework to model the strategic interaction between a leading national-brand manufacturer and a retailer. Besides the national brand, the retailer also has an option for its own store brand to compete with the national brand head to head. There are two choices for the store-brand production available to the retailer: a fringe manufacturer with low production efficiency or alternatively the nationalbrand manufacturer with high efficiency. It is shown that, under certain conditions, there is a win-win situation for both the storebrand retailer and the national-brand manufacturer with the latter supplying the store brand. More interestingly, it is found that the national-brand manufacturer supplying the store brand may lead to a higher likelihood of the store brand introduction. Our study offers an explanation for why more and more national-brand manufacturers supply store brands.