Firing on all cylinders, Pakistan's Mansoor Zaman upset second seeded Ong Beng Hee of Malaysia in the final to emerge champion in the three-star US $30,000 Kolkata International Squash tournament on Saturday.

World number 35 and tournament fifth seed Mansoor won 11-8, 11-7, 4-11 and 11-8 in only 54 minutes to pocket US $4,873 before a sizeable crowd at the Calcutta Racket Club.

It was clearly Mansoor's day as he displayed great variety and let loose a flurry of attacking shots which world number 16 Beng found too hot to handle.

Mansoor pocketed the first two games in style, as Beng looked lacklustre and made to run around the court by the Pakistani, who happens to be the son of former World champion Qamar Zaman.

Mansoor made his aggressive intent clear from the outset and went for the kill at the slightest opportunity. But Beng recovered some lost ground in the third game as he executed good smashes and rolled in a few to close the gap.

The Malaysian took the game as Mansoor hit down, triggering expectation among the spectators of a more competitive fourth game.

True to the crowd's hope, the two players engaged in a see-saw battle, with fortunes swinging from one end to the other.

Beng began well, opening up a 3-0 lead, but the Pakistan player restored parity at that score.

The Malaysian again took a 6-4 lead, but then conceded a couple of negative points as Mansoor staged a smart rally to gain five consecutive points and move ahead to 9-6.

The two players fought a close battle, before Mansoor finally sealed the title riding on two strokes given against is opponent.

"I played well throughout the tournament. I trained hard for this event over the last two months. He (Beng) gave me a hard time. But since we keep meeting on court, we know each other's game very well. Beng is very good on the back court so I concentrated on hitting drops from the back court itself," said a joyous Mansoor.

The Pakistan player, who aims to get into the top ten this year, said Beng gave him lot of open spaces in the first two game.

"I lost concentration in the third game, but kept myself motivated in the fourth," Mansoor said.

Beng, who bagged US $3,300, had no hesitation in admitting Mansoor's superiority.

"He showed why he was world number 11 earlier. He completely destroyed me. Today was clearly his day. I don't remember having seen him play so well earlier. If he plays like this, he can be in the top ten soon."