Boonsak sank to his knees and pumped his fist after a 36-minute, 21-17 21-14 demolition of shell-shocked world No 6 Chen Yu of China.

It has been a barren three years for world No 11 Boonsak, the beaten semi-finalist at the Athens Olympics.

His last big win came in the 2004 Thailand Open when he produced superb form to top Malaysian Lee Chong Wei.

The calm Thai was not among the favourites in the star-studded tournament. Yet, in the quarterfinals Boonsak lived up to his nickname, the Thai Superman.

He put up a splendid fight to oust world No 1 and favourite Lin Dan of China, in a hard-fought three-game thriller 21-17 7-21 23-21.

"I tried to attack whenever there was a chance because he is an attacking player and I could not let him control the pace," Boonsak, 25, said.

"I think Lin was not used to the condition of the court and he may have been putting too much pressure on himself while I had nothing to lose. It's probably the best victory of my life. I'm delighted to prove that Lin is not indomitable."

He continued his fine run in the semis breaking Singaporean hearts when he stopped local hero Ronald Susilo in a one-sided 21-13 21-15.

Boonsak was cool under fire in the final. Chen Yu was last year's Thailand Open champion and in March beat the Thai player in the last 16 of the All-England Super Series.

Trailing the Chinese challenger 10-13, he hit back aggressively with superb net play and excellent drop shots to win the opener 21-17.

The second was thrilling as both men attacked from the outset. Boonsak was unstoppable as he won the game 21-14, the match and the crown. He takes home US$16,000.

"I am just so happy. The Thai fans were cheering me. I did not want to let them down again and again. I gave all I had," a delirious Boonsak said.

"I want to be a champion again," he added, already looking ahead to the Indonesia Open in the coming week, the sixth leg of the badminton Super Series.

Meanwhile, Indonesian eighth seeds Flandy Limpele and Vita Marissa shattered Thai dreams of a two-title sweep when they stunned third-seeded Sudket Prapakamol and Saralee Thoungthongkam, bronze medallists in the previous two World Championships, 21-14, 21-13 to lift the mixed doubles.