John Isner continued his stranglehold on the Atlanta Open by winning back-to-back titles at the expense of Ryan Harrison.

Defending champion and top seed Isner, 33, claimed his fifth Atlanta crown after rallying past fellow American Harrison 5-7 6-3 6-4 on Sunday.

Isner dropped the opening set against the eighth seed but the big-serving American responded in the second, saving four break points and converting one of his own to level the final.

A Wimbledon semi-finalist this year, Isner carried on where he left off in the third and deciding set as he broke Harrison early before closing out the contest to love in the 10th game.

With his second ATP title of the year, Isner joined Jimmy Connors, John McEnroe, Andre Agassi and Pete Sampras as the only Americans to win five or more titles at a single tournament.