Fritz, the No. 4 seed and the runner-up to Jannik Sinner at Flushing Meadows a year ago, needed about 10 fewer minutes to move on with a 7-5, 6-2, 6-3 victory over yet another U.S. man, Emilio Nava, a wild-card entry, at Louis Armstrong Stadium.

There's a larger contingent of Americans in the US Open men's bracket than at any time in the past quarter-century, and two of the leaders -- Taylor Fritz and Ben Shelton -- got the tournament started on Sunday with dominant performances.

Ben Shelton dispatched Ignacio Buse 6-3 6-2 6-4, prevailing without losing serve whereas Taylor Fritz triumphed 7-5 6-2 6-3