Takehiro Nonaga (1:18:56.0) came in just 10 seconds ahead of Sarawut Ngamsri (1:19:06.6) to win Thialand’s oldest road run.
More than 1,300 runners took part in the 34th annual River Kwai International in Kanchanaburi.
The race for third was even closer with Nattapat Sonprasan (1:27:12.1) holding off Thapakorn Ngamsri (1:27:21.5).
For the women, it was Monika Kovarikova (1:39:33.1) cutting more than four minutes from her fourth-place finish a year ago, to take the top spot.
Madolyn Smith secured second with a time of 1:40:29.0.
Tritthaporn Kaewsok (1:41:51.5)finished ahead of Punyanuch Phechayanipon (1:42:05.8) for third.