Rate-dependent phenomena induced by impacts are paramount to the design of protective structures. Such events trigger rapid microstructural evolution, pronounced nonlinear deformation, plastic flow, fracture, fragmentation, and thermal softening in ductile materials. Modelling these coupled mechanisms remains challenging, since many existing approaches rely on ad-hoc parameters with limited physical justification, often leading to unphysical responses under different loading conditions and poor scalability. To address these limitations, we formulate a continuum framework grounded in the rigorously established principles of classical continuum mechanics. However, to overcome the intrinsic bottleneck associated with the requirement of sufficient differentiability of field variables in the classical theory, spatial derivatives are reinterpreted using a stochastic gradient estimator (SGE). This formulation naturally incorporates nonlocality and microstructural effects in thermo–visco–plastic deformation subjected to impact loading. It remains well-posed even in the presence of field discontinuities, without the need for additional restrictive prescriptions. Failure is governed through the Johnson–Cook damage model, and material-point interactions are terminated once the damage variable reaches a critical threshold. The proposed framework accurately predicts the failure response of a Weldox 460E target and the associated projectile velocity histories, showing strong agreement with experimental observations. Apart from its accuracy and robustness, perhaps the most exciting aspect of the SGE-continuum mechanics is that it appears to be orders-of-magnitude faster in comparison to its traditional finite element or particle-based (e.g. SPH) counterparts. These results demonstrate that the method advances beyond the limitations of conventional numerical techniques and enables robust, physically consistent analysis of complex impact mechanics problems.