Ryan Sweeting won his first ATP Tour title by beating Kei Nishikori in the US Clay Court Championships final.
The 23-year-old American wild card saw off the Japanese sixth seed 6-4 7-6 (7-3) in Houston.
Sweeting, trailing 5-4 in the second set, had to overcome three set points on his own serve before holding on a lob error by Nishikori.
In the tie-break, he double-faulted to make it 3-3 but two errors by Nishikori saw him close in on victory.
A forehand volley winner by the brought the contest to match point and it ended when a Nishikori forehand skipped wide.
Sweeting's win capped a fine week's work which also saw him defeat second seeded compatriot Sam Querrey and former champion Ivo Karlovic.
He is the first wild card to reach the Houston final since Mardy Fish won in 2006 and the fifth first-time winner on the ATP Tour this year.
Sweeting fell to the ground in jubilation and fatigue after a hard-fought second set and later took a victory dive into the pool at the Oaks Country Club.
"I needed a little help to get in. I want to thank [the organisers] for the opportunity, and for giving me the wild card," he said.
"It was a lot of fun. I'm looking forward to coming back and defending the title next year."
Sweeting will move up to a career-best world ranking of 71st after his win.