DELRAY BEACH, Fla. — Qualifier Kei Nishikori became the first Japanese man to win an ATP title in 16 years by upsetting top-seeded James Blake 3-6, 6-1, 6-4 in the International Tennis Championships final today.

"I still can't believe it that I beat James Blake," the 18-year-old Nishikori told the crowd, which included a dozen Japanese fans chanting "Nippon! Nippon!" high up in the stands. "I've only seen him on TV. This is my best tournament ever."

He is the youngest player to win an ATP title since Lleyton Hewitt won Adelaide as a 16-year-old in 1998.

Shuzo Matsuoka as the last tournament champion from Japan. He won his lone career title at the Seoul tournament in April 1992.

Nishikori used deep ground strokes and a multifaceted game to win eight matches in the tournament, three in qualifying and five in the main draw. He saved four match points in his semifinal against third-seeded American Sam Querrey.

Blake, who appeared to emotionally fade at times in the match, was quick to credit Nishikori as a future star.

"Congratulations to Kei on winning his first ATP title," Blake said. "I'm sure it will be one of many. He's been impressive all week. He has a very bright future."

Blake, 10 years older than Nishikori and currently ranked 12th, has failed to capture the title in two consecutive final appearances at the ITC. Blake was the third top-seeded player to reach the final at this tournament since it began in 1993. None of the three captured the title.

"I can't seem to get that winner's title so I'll have to keep coming back and trying," Blake said.

Blake took control of the first set when he broke serve in the eighth game. From there, the match belonged to the Japanese teen, who took a 5-0 lead in the second set before Blake managed to get on the scoreboard.

In the third set, Nishikori saved three break points on his own serve in the second game. Blake then squandered two game points to have his serve broken at ad-out when Nishikori sent a backhand floater down the line.

Nishikori, who has trained at the Nick Bollettieri Academy the past three years, earned $68,800. Blake won $37,350.