In the search for natural alternatives to control fungal diseases, antagonistic fungi are valuable sources to find new models. In the present study, a total of 41 tropical micromycetes were isolated from plant debris submerged in sinkholes of the Yucatán Península. All strains were tested in antagonist assays against four phytopathogenic fungi (Colletotrichum gloeosporioides, Corynespora cassiicola, Curvularia sp. and Fusarium sp.). Results of the antagonistic assays showed mycelial growth inhibition (MCI ≥50 %) by 17 isolates (41 %) against at least one of the targets tested. The highest inhibition was exhibited by the Hypocrea lixii OSN-37 (MCI=61-77%) and Rhizoctonia solani OSE-73 (MCI=55-64%) strains against all targets while Pestalotiopsis mangiferae OH-02 (51-59%) caused inhibition on three of four pathogen strains. These three strains were cultured in fermented rice to obtain their ethyl acetate and methanol extracts which were tested against C. gloeosporioides using the microdilution assay. Results showed H. lixii OSN-37 and R. solani OSE-73 to be producers of antifungal metabolites as one of their modes of action. In conclusion, three promising antagonistic native strains were isolated from plant debris submerged in the Yucatán sinkholes, representing a valuable contribution to the development of ecofriendly alternatives to control fungal diseases in agriculture crops of the tropical regions.