Peanut (Arachis hypogaea L.) is a vital global crop, particularly in tropical and subtropical regions. However, its production is severely impacted by early leaf spot (ELS), caused by Passalora arachidicola (PA), and late leaf spot (LLS), caused by Nothopassalora personata (NP), leading to significant yield losses and management costs. This study evaluates peanut genotypes with resistance to ELS and LLS, comparing them to susceptible cultivars. It explores both pre-infection resistance components, including reduced conidial adhesion and shorter germ tube length, and post-infection components, such as lower lesion incidence, reduced disease severity, and delayed sporulation. Results suggest that genotypes with resistance from Arachis cardenasii, Arachis stenosperma, and Arachis batizocoi exhibited delayed pre-infection and post-infection processes for PA and NP, while susceptible cultivars exhibited faster infection processes. These findings enhance our understanding of the genetic basis of resistance to leaf spot pathogens and lay the groundwork for future research.