John Isner joined elite company when he saved four of five break points en route to beating compatriot Ryan Harrison to win the Atlanta Open for the fifth time.

The top seed Isner beat the eighth-seeded Harrison 5-7 6-3 6-4 at Atlantic Station – his second final win over his fellow American in as many year.

Isner, 33, became the fifth American man to win the same event at least five times after Jimmy Connors, John McEnroe, Pete Sampras and Andre Agassi.

But it was tough going at times for Isner with Harrison taking the first set and the better player early in the second.

Isner appeared to be wilting in the heat but Harrison could not take his chances and his opponent squirmed out of trouble before pouncing when presented with a break opportunity.

A revitalised Isner never looked back in the third set as Harrison’s frustration finally boiled over and he smashed his racket against the court.

Isner improved to 31-4 in the event – winning three straight titles in Atlanta from 2013-15 and losing the 2016 final to Australian Nick Kyrgios.

The 6-foot-10 former University of Georgia has 14 ATP Tour titles, breaking through for his first ATP Masters 1000 success at the Miami Open in April.