The non-equilibrium adsorption of a single non-grafted polymer to a flat surface is investigated. Using Brownian dynamics simulations we consider the influence of a lateral external force applied on one end of the polymer, as experimentally realized in AFM pulling experiments. The external force flattens the chain perpendicular to the pulling direction and hence favors the chain adsorption; this mechanism is rationalized in terms of a renormalization of the polymer Kuhn length. Our results are also relevant for polymer adsorption in elongational or simple shear flow and for sheared polymer brushes in contact with an adsorbing substrate.