An efficient Navier-Stokes solver for the infinite-swept wing problem is presented. The new flow solution, that reproduces correctly the physics responsible for cross-flow effects, is obtained around a two-dimensional stencil. On the contrary, existing state-of-the-art methods rely on a three-dimensional stencil. Numerical details are followed by an extensive validation campaign, including steady and unsteady compressible flows. The test cases are for single and multielement aerofoils in both laminar and turbulent regimes. Under identical conditions (numerical settings, grids, etc.), the computational cost of the proposed solver was reduced by at least 75% compared to that of existing state-of-the-art methods. This was also confirmed employing various turbulence models. With a limited effort required to enhance an existing computational fluid dynamics solver (either two or three-dimensional), the infinite-swept wing method was implemented in an industrial-grade package used across Europe for rapid engineering analysis.