Plant chitinase is a pathogenesis-related protein that can hydrolyze chitin, the main component of fungal cell walls, and plays an important role in plant disease defense responses. Our previous study found the sugarcane class IV chitinase gene ScChiIV1 (GenBank Accession No. KP165001) was responding positively to smut pathogen Sporisorium scitamineum stress, but its disease resistance function and mechanism were unclear. Here, the upstream promoter of the ScChiIV1 gene (pro-ScChiIV1) with a length of 1696 bp was cloned which contained cis-acting elements related to hormone and stress response. Transient overexpression of the pro-ScChiIV1 in Nicotiana benthamiana showed inducible transcriptional levels by ABA, Fusarium solani var. coeruleum, and Alternaria longipes stimuli. Furthermore, stable overexpression of the ScChiIV1 gene in N. benthamiana enhanced the resistance of transgenic plants against F. solani var. coeruleum and S. scitamineum. Phenotypic monitoring, relevant physiological indicators, immune-related gene expression, and transcriptome analyses revealed that ScChiIV1 may activate potential TFs and PKs by inducing Ca