The championship is taking place until May 2 at Crucible Theatre in Sheffield, England.
Thepchaiya, 53rd in the world, went up against four times world champion Higgins in the first round of the main competition.
The Thai took a lead with a score of 5-4 in the first session, but Higgins came back in full force and won 10-7.
Higgins now goes into the second round and will face either Luca Brecel from Belgium or Thailand’s Noppon Saengkham which will be decided on Thursday.
Thepchaiya isn't going home empty-handed: he bagged a worthy prize of £20,000, or around THB880,000.