Nadal, who won his 19th Grand Slam title in New York, had earlier overcome Canada’s Raonic 6-3, 7-6 (7/1) after defending eight break points in the first set.
Mike Bryan teamed with Jack Sock for only their second tournament together, and the American duo edged Raven Klaasen of South Africa and Michael Venus of New Zealand 6-3, 6-7 (7), 6-3, 5-7, 7-5 on Saturday night in the final at Centre Court.