American second seed Ben Shelton saved three match points before battling back to defeat top-seeded compatriot Taylor Fritz 3-6, 6-3, 7-5 and capture the ATP Tour's Dallas Open on Sunday.
Shelton looked to be on the brink of defeat after trailing 15-40 at 4-5 down to the big-serving Fritz in the decisive final set.
But the 23-year-old from Florida showed superb composure to dig his way out of trouble with a ruthless smash to save the first match point before lasering a forehand into the corner to go to deuce.
Fritz earned a third match point when Shelton sent a forehand into the net, but once again he was unable to convert as his opponent saved again before going on to hold at 5-5.
Fritz's composure on serve then deserted him in the next game, when his first double fault of the match presented Shelton with three break points at 0-40.
Shelton took advantage to secure the break for a 6-5 lead before holding to complete victory and clinch the fourth ATP title of his career in 1hr 52mins.
Shelton greeted victory by praising Fritz, who has struggled with knee and oblique injuries this season.
"This was a crazy match to be part of," Shelton said, before addressing Fritz. "I thought your level was amazing. What you've done this year, dealing with adversity, fighting through injuries, the competitor you are – you're an inspiration to all.
"Every kid at home should watch how hard you compete, day in and day out when you're not feeling 100 percent."
Fritz, meanwhile, rued his inability to build on an impressive opening set when he looked in complete control.
"It was a fun match to be a part of up until the end," Fritz said. "But congrats to Ben – he played the big points and important moments really good."