Marin Cilic overcame Mardy Fish in three sets to win the Pilot Pen tournament in Connecticut.
Cilic, the sixth seed, won 6-4 4-6 6-2 as Fish suffered defeat in the final for the second successive year, having lost out to fellow American James Blake 12 months ago.
It is the first ATP Tour title of his career for Croatia's Cilic, who goes into next week's US Open ranked 31st in the world.
The 19-year-old won five of six break points en route to becoming the eighth first-time winner on tour this season and travels to Flushing Meadows full of confidence.
"I am feeling very excited," said Cilic.
Ups and downs
"The match was a little bit thrilling. There were a lot of ups and downs from both of us but eventually in the third set, I got my thoughts back and my rhythm. I was really pumped up when I had to be.
"I had a great week, won matches against good players. I'm feeling physically well so I hope that I'm going to continue with this good form at the US Open and make some progress there."
For Fish, it was his ninth defeat in a final as a first title since Houston in 2006 eluded him.
"I would have liked to have played better," a despondent Fish conceded.
"This is my 11th final and I've only won twice. It's starting to really sting. I've got a lot of runner-up trophies in my office in my house. These are the ones I need to get.
"This was a great opportunity for me tonight, to get my third title."