Thailand's Prayad Marksaeng swept to victory on home soil at the Queen's Cup in Koh Samui Sunday shooting a six-under par 65 on a day that proved to be a nightmare for Japan's Akinori Tani.

Prayad's fortunes waxed and waned during round four of the $300,000 Asian Tour title as the 49-year-old made up for three bogeys with nine impressive birdies, comfortably taking the top spot with a final score of 270.

Fellow Thai Thanyakon Khrongpha matched Prayad's 75 to jump up the leaderboard to second on 272, closely followed by compatriot Jazz Janewattananond and Bangladesh's Siddikur Rahman who ended four strokes off the lead in joint third.

Tani had begun the day a comfortable three shots ahead of the pack but repeatedly floundered at the Santiburi Samui Country Club under hot and humid skies.

By hole 14 he had racked up half a course of bogeys. He ended the day on a way over-par 75 and an ignominious joint sixth of 277.

Only a day earlier he had stormed round the same course with a seven-under-par 64, the best score of the tournament.

Prayad, a now nine-time Asia Tour winner, last took home the Queen's Cup trophy in 2013.

Finishing scores on day four:

270 - Prayad Marksaeng (THA) 69-65-71-65

272 - Thanyakon Khrongpha (THA) 74-65-68-65

274 - Jazz Janewattananond (THA) 69-72-67-66, Siddikur Rahman (BAN) 69-70-67-68

276 - Mithun Perera (SRI) 67-72-68-69

277 - Paul Peterson (USA) 69-72-68-68, Richard T. Lee (CAN) 69-67-71-70, S.S.P. Chawrasia (IND) 73-67-67-70, Akinori Tani (JPN) 68-70-64-75
Source: AFP