This paper studies the semi-global sampled-data stabilization problem via output feedback for a class of uncertain nonlinear systems under mismatched uncertainties and a higher-order, rather than linear growth lower-triangular condition. A systematic design scheme is developed to construct a linear output feedback control law in sampled-data form that semi-globally stabilizes the uncertain nonlinear system. By extending the output domination approach and restraining the state growth under a zero-order-hold input with the help of Gronwall-Bellman Inequality, explicit stability analysis procedures are presented for the hybrid closed-loop system. With less control ambition, the proposed semi-global sampled-data controller consists of a set of linear difference equations which will lead to easier digital implementations.