Binoculars swinging around their necks, Thai punters erupt into cheers as horses round the final bend - the thrill of the race amplified by the rare chance to gamble in a Buddhist country where betting is virtually banned.

"I come every week, I love horses," says 66-year-old Chumpon Aunaeksri, eyeing the thoroughbreds as they trot onto the turf at the downtown Bangkok course, which is fringed by tower blocks.

The stadium's scuffed concrete stands are filled with thousands of other race fans, mostly elderly men, snacking on peanuts and sipping beer as cigarette smoke wafts through the sticky city air.