Rice blast, caused by Pyricularia oryzae, is one of the most destructive diseases in agriculture leading to severe impacts on rice crop harvests worldwide. In a previous study, we showed that rice genes OsDjA2 and OsERF104, encoding a chaperone protein and an APETELA2/ethylene-responsive factor, respectively, were strongly induced in a compatible interaction with blast fungus, and also had their function in plant susceptibility validated through gene silencing. Here, we report the CRISPR/Cas9 knockout of OsDjA2 and OsERF104 genes resulting in considerable improvement of blast resistance. A total of 15 OsDjA2 (62.50%) and 17 OsERF104 (70.83%) T0 transformed lines were identified from 24 regenerated plants for each target and used in downstream experiments. Phenotyping of homozygous T1 mutant lines revealed not only a significant decrease in the number of blast lesions but also a reduction in the percentage of diseased leaf area, compared with the wild-type infected control plants. Our results supported CRISPR/Cas9-mediated target mutation in rice susceptibility genes as a potential and alternative breeding strategy for building resistance to blast disease.