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.

There is none of the glamour associated with the international racing circuit.

In Thailand it is all about the sport - and of course the chance to openly enjoy a flutter in country with tough anti-gambling laws.

A former jockey himself, Chumpon has seen his fortunes wax and wane over the years, winning 20,000 baht ($570) on one Sunday only to lose 100,000 ($2,845) on another.

Lately, he has endured a painful losing streak.

"But it's okay, it's all legal here," he says.

Not so for underground casinos or even friendly backyard card games - which are routinely broken up by police and soldiers in the country.

Even elderly bridge players are not exempt, with a squad of security officers hauling a pack of retired Brits over to the police station in the beach town of Pattaya last year for violating a ban on owning more than 120 playing cards.

Horse racing was first brought to Thai soil a century ago under King Chulalongkorn, an anglophile monarch credited with modernizing Thailand and fending off the colonial powers who had carved up the rest of the region.

After enjoying a race put on by Thais who had seen the sport abroad, the king bestowed a plot of land in the capital to become Thailand's first course.

Racing quickly bloomed.

But harder times have befallen the industry in recent years as younger Thais increasingly fixate on football.

Bangkok's two tracks still sell some 6,000 tickets each per race day, turning over around 40 million baht ($1.1 million).

But that is a steady drop-off from Thai racing's heyday before the 1997 economic crisis, when the clubs raked in three times as much.

Race-rigging also remains all too common - giving horse owners the upper hand when it comes to closing the day with extra cash.

In the absence of transparency, regular punters know the safest bet is to follow the VIPs' lead.

"If there are many people betting on a horse, I'll just go for that one," explained 79-year-old Preecha Sridama, a race devotee since since he was 20.

"But it's never certain," he adds, peering back down at his notes for the next race.