Thailand's Danthai Boonma won the US$400,000 Bangabandhu Cup Golf Bangladesh Open today after an enthralling two-horse race with close friend and compatriot Kosuke Hamamoto.

Danthai fired a closing three-under-par 68 at Kurmitola Golf Club, in Dhaka, for a four-round aggregate of 13-under-par 271 and a one-shot victory over Hamamoto, who carded a 70.

Rattanon Wannasrichan made it a one, two, three finish for Thailand after returning a 67 to finish three behind the champion.

Bangladesh's golfing idol Siddikur Rahman, despite being roared on by strong local support, closed with a 70 to finish in a group of four players tied for fourth, six back from top spot.

Danthai started the day one behind playing partner Hamamoto but a brilliant front nine of three under, which included birdies on seven, eight and nine saw him make the turn one ahead.

It was a lead he did not relinquish, with both players coming home in even par, and allowed him to add the National Open of Bangladesh to The World Classic Championship he claimed at Laguna National in Singapore in 2015.

"I'm so excited about my second win on the Asian Tour," said Danthai, who dined out with Hamamoto for much of the week.

"Yeah, nothing to say but I can't believe it, because it's been tough in the past two years, I didn't really play very good you know. I mean, I struggled with my mind and my short game, so I tried to figure out about those things. And yeah, I can't believe it about this week."

He won the Boonchu Ruangkit Championship on the Asian Development Tour in 2016 before the drought set in.

He added: "I started very good, on my second hole I got a birdie. Then the third hole is a bit tough because it's a long par four and a little bit narrow, but I could make a par on that hole. After that I had a three putt on number six the par three. Then I just tried to keep my momentum, and keep my mind clear of everything, and just keep my plan and just do what I want to do.

"Yeah, actually Danthai and I ate dinner together every day, we're close friends and we practice together. It was a bit tight you know, I tried to keep fighting and just keep focus, just relax and focus."

Hamamoto, the SEA Games gold medal individual winner in 2017, was in pursuit of his first victory on the Asian Tour and despite finishing second he was more than happy with his performance.

"It was a very fun round today," said the Thai golfer, whose father is Japanese and mother Thai.

"I definitely felt the nerves out there, but I am very happy with how my game is trending. I just need to stay patient and do the same thing and I think my time is coming soon. I am really proud of how I handled myself."

There was no hiding the disappointment of Rahman's fans; the country's star golfer was bidding to win the tournament for the first time since it joined the Asian Tour in 2015.

"My hitting was totally off, so I'm not happy with my hitting," said the two-time Asian Tour winner, who won this event in 2010 when it was part of the Professional Golf Tour of India.

"But I made a few up and downs which was very good. But overall, I still played one under so it's okay, but my especially my hitting was totally off today and yesterday.

"Overall, it was okay, the course condition was really awesome. Normally we are not used to playing the course in this condition. So overall it was a wonderful week for me."

Thailand's 15-year-old amateur ace Ratchanon Chantanuwant, aka "TK", made a sensational start by touring the front nine in four under with four birdies in the first five holes, but the wheels came off on the back nine with a double bogey on 10 and a triple on 13 contributing to a back nine of 43. He closed with a 74 and tied for 29th, on one under.

Defending champion Sadom Kaewkanjana from Thailand signed off with a 72 to end two over in equal 42nd.

The Asian Tour heads to its season ending event next week, the US$1.5 million BNI Indonesian Masters presented by TNE at Royale Jakarta Golf Club, from December 1-4.