A 2D lattice-gas numerical algorithm was used to simulate liquid infiltration into unsaturated porous media with a parallel sided central crack. The chosen model, the interacting liquid-gas model of Appert and Zaleski, has dynamic properties leading to a phase transition and liquid and gas phases can be simulated by the model. These two phases are used to simulate biphasic flow in porous media. Fourteen numerical experiments of liquid infiltration were carried out which differed in the morphology of the microporous matrix, in the aperture of the central crack and in the amount of liquid supplied. For the same microporous matrix, the infiltration dynamics in the dual media depended upon the ratio between the amount of liquid supplied and the crack aperture. Variations in water storage over time and liquid flow regimes within the cracks are discussed.