Police were called to the Khao Lan intersection at 1:30am.
They found 34-year-old Mr Suriya Chaiyakul of Thalang lying in a pool of blood, dead. About 80 metres from his orange-and-black Kawasaki 800cc motorbike was a full-face helmet.
Nearby was a Honda Click and the three people who were riding it.
The driver, 26-year-old Pratchaya Chantachum driver of Udon Thani, and 24-year-old Rattanawit Junsena, also of Udon Thani, were rushed to Thalang Hospital, where they are in critical condition.
The third man on the Honda Click, Wijit Konsong of Khon Kaen, told police that he was on the back of the motorbike with his friends, but jumped off in time to avoid injury.