But a viral video showed the jubilant scene of cheering fans in his rural hometown transform into tragedy after his grandmother, Subin Khongthap, collapsed while watching the competition on a projector.

"The initial assumption is that she died from heart failure - but we have to wait for the hospital's result," said Somwang Prangprakoan a police officer in northeastern Surin province.

"I'm not sure if she was too excited, or if maybe she was already ill," he added.