The title compound, C19H12ClF3O3, obtained by the photochemical transformation of 2-[5-chloro-2-(prop-2-ynyloxy)benzoyl]-3-[4-(trifluoromethyl)phenyl]oxirane adopts a Z conformation with respect to the enolic C=C double bond. The dihedral angle between the benzene rings is 12.25 (16)° and an intramolecular O—H...O hydrogen bond closes an S(6) ring. An intramolecular C—H...O interaction also leads to an S(6) ring. In the crystal, very weak C—H...O interactions and short Cl...Cl contacts [3.3221 (16) Å] are seen, as well as weak aromatic π–π stacking interactions [centroid–centroid separation = 3.879 (2) Å].