This technical note considers the stability of a class of singularly perturbed hybrid systems with a continuous slow subsystem. This type of system encompasses many slowly-varying adaptation schemes, such as extremum-seeking, acting on hybrid systems, such as urban traffic control and switching control. Conditions are given for semi-global practical asymptotic stability of the closed-loop system when the dynamics of the reduced system are also semi-globally practically asymptotically stable. This extends previous results which require global asymptotic stability of the reduced system. Furthermore, the stability result is used to show convergence of an extremum seeking scheme acting upon a hybrid system.