Annona squamosa L., a vital tropical fruit crop in southern China, faces escalating threats from fungal diseases, though rust pathogens had not been previously documented domestically. This study reported the first dectection of Phakopsora cherimoliae, a high-risk rust fungus known to cause severe yield losses (>30%) in Central and South America, detected in Yunxiao county, Fujian province. Field symptoms included chlorotic flecks on adaxial leaf surfaces progressing to reddish-brown necrotic lesions with abaxial yellowish-brown uredinia. Morphometric analysis revealed ellipsoid to ovoid urediniospores, long axis is (28.0±2.5)μm; short axis is (22.7±3.2)μm, consistent with P. cherimoliae descriptions but notably smaller than those reported on A. cherimola hosts, suggesting potential host-driven morphological adaptation. Molecular characterization via LSU rDNA sequencing indicated that the sequence of the three isolates obtained in this study exhibited over 99% identity with the reference strain KF528012. Phylogenetic analysis using maximum likelihood and the Kimura-2 parameter method positioned the isolates in a distinct monophyletic clade with 100% bootstrap support, separate from other related Phakopsora species. Pathogenicity was confirmed through Koch's postulates. Inoculation of healthy Annona trees with filed urediniospores induced identical symptoms and new urediniospores within 14 days. The absence of telia indicated dependence on urediniospores for asexual propagation, raising concerns about persistent epidemics under Fujian's humid subtropical climate, where monsoon winds may facilitate regional dispersal. Urgent management strategies include pre-monsoon application of tebuconazole, systematic removal of infected debris, and resistance screening across commercial cultivars (e.g., ‘African Pride’). Study limitations include unresolved telial stage biology and unquantified spore dispersal dynamics, warranting long-term phenological monitoring and aerobiological modeling. This invasion event underscores vulnerabilities in China's tropical fruit biosecurity, emphasizing the imperative for enhanced phytosanitary surveillance and international collaboration to mitigate cross-border pathogen spread. The findings establish a critical baseline for rust disease management in Asian Annona production systems, bridging a longstanding gap in regional plant pathology literature.