Target Corp. posted a surprise increase in third-quarter profit as sales in the U.S. topped the company's own expectations, a promising start to the tenure of new Chief Executive Brian Cornell who's trying to restore luster to the big-box retailer. Target's profit rose 3.1% in the period as sales at established U.S. stores rose 1.2%, ahead of the company's August projection of same-store sales rising up to 1%.