Ireland Women slumped to their third loss of the Quadrangular tournament, and their second in four days against Thailand.
The side looked to have turned a corner with a dominant batting display on Monday against the Dutch, but they found the Asian side's bowling unit an altogether much tougher prospect.
Gaby Lewis (2) fell early and fellow opener Rebecca Stokell went for a run-a-ball 17.
The experienced middle-order trio of Kim Garth (16), Mary Waldron (21) and Laura Delany (22) failed to break the shackles and when rain ended the Irish innings prematurely, the Girls in Green had stuttered to 87 for 8 in the 17th over.
The Thais were set a DLS target of 64 in 11 overs, and despite tight bowling by the Irish unit, they were always in control, securing the win in the final over.
Ireland will conclude their disappointing tournament on Wednesday against Scotland, looking to end the competition on a high ahead of the T20 World Cup Qualifiers at the end of the month.