Mardy Fish of the US returns a volley to compatriot John Isner during the finals match of the Atlanta Tennis Championship in Norcross, Georgia, July 24, 2011. [Photo/Agencies]

ATLANTA - World number nine Mardy Fish saved two match points in recording a 3-6 7-6 6-2 victory over fellow American John Isner to defend his Atlanta Tennis Championship title on Sunday.

In a repeat of last year's final, American No.1 Fish was deep in trouble in the second set tiebreak when he trailed 5-1 and 6-4 but reeled off four straight points to take the match into a decider at the racquet Club of the South.

The momentum carried over to the third set as Fish broke Isner in the first game and then held to love.

"When you're in that position, it's almost over," Fish told the ATP Tour website.

"I was lucky to get out of it. I stuck some returns and put some balls in play. I played some good points from then on."

Isner was unable to capitalise on two break points in the sixth game of the decider, then gifted another break to Fish when he double-faulted twice to fall behind 5-2.

"I ran out of gas in the third set," Isner told the Atlanta Journal Constitution. "I didn't feel my best. Maybe it was the heat. I don't know what it was but it was the difference in the third set."

Fish closed out the match to win his sixth title and deny Isner a consecutive trophy after he won on the Newport, Rhode Island grasscourts two weeks ago.

The Atlanta tournament is the first in the US Open series which culminates in the Flushing Meadows grand slam.