This article presents a new switching control scheme for controlling a class of nonlinear discrete-time dynamical systems. The key idea behind the proposed control techniques lies in the decomposition of unmodeled dynamics, that is, the unmodelled dynamics are decomposed as a sum of a known function depending on the data from the posterior unmodeled dynamics measurement and an unknown increment. The control algorithm is based on a novel estimation algorithm for the increment of unmodeled dynamics, which contributes two nonlinear controllers. The theoretical results on both convergence and stability of the closed-loop system are given. The system performance is evaluated by some simulation results.