The paper presents the semi-numerical solution for the magnetohydrodynamic (MHD) flow due to nonlinear porous shrinking sheet caused by boundary layer of an incompressible viscous flow. The governing partial differential equations of momentum equations are reduced into ordinary differential equation by using a classical similarity transformation along with appropriate boundary conditions. Both nonlinearity and infinite interval demand novel mathematical tools for their analysis. We use fast converging Dirichlet series and Method of stretching of variables for the solution of these nonlinear differential equations. These methods have the advantages over pure numerical methods for obtaining the derived quantities accurately for various values of the parameters involved at a stretch and also they are valid in much larger parameter domain as compared with HAM, HPM, ADM and the classical numerical schemes.