The 21-year-old Latvian, ranked 72nd in the world, didn't drop a set all week and made the most of his first career final as he became the first Latvian to win a title.

"Everything I do it's the first for my country," Gulbis said. "I was first one in top 300, first one in top 200, first one in top 100."

Now he's poised to move into the top 40 in the world when the new rankings are announced on Monday.

Gulbis said his dominance during the week wouldn't have mattered if he hadn't come through on Sunday.

"So I didn't lose a set, I don't see that as a big accomplishment," he said. "I think winning a title is a big accomplishment."

Gulbis broke the big-serving Croatian twice in each set.

Croatia's Karlovic, who celebrated his 31st birthday on Sunday, did save three match points with aces in the final game, but double-faulted on the final two points to surrender the match.

"I would like to thank him for this gift on my birthday," Karlovic quipped. "Everything he touched with his racket today was unbelievable, a clean winner."

Gulbis became the second player this year to win a title in his first finals appearance. American John Isner won the Auckland title in his first trip to a championship match last month.

Despite the fact that it was his first final, Gulbis never looked nervous as he displayed an impressive array of shots to deny Karlovic a fifth career crown.

"He was really cool, calm, like nothing could impress him," Karlovic said.

"This year he's going to make a breakthrough."