NEW YORK — Fabio Fognini, the newly minted husband of Flavia Pennetta (who happens to be the 2015 US Open champion), has been causing scenes in New York—and he's only played one match.

Life is good for Fabio Fognini. In April, the gregarious Italian won the biggest title of his career at the Monte Carlo Masters in Monaco, about 25 miles from his home in Sanremo. “I was ...