A receiver-extension strategy is presented as an alternative to recently promoted source-extension strategies, in the framework of high-resolution seismic imaging by full-waveform inversion (FWI). This receiver-extension strategy is directly applicable in time-domain FWI, and, unlike source-extension methods, it incurs negligible extra computational cost. After connections between different source-extension strategies are reviewed, the receiver-extension method is introduced and analyzed for single-arrival data. The method results in a misfit function convex with respect to the velocity model in this context. The method is then applied to three exploration-scale synthetic case studies representative of different geologic environments, based on the Marmousi model, the BP 2004 salt model, and the Valhall model. In all three cases, the receiver-extension strategy makes it possible to start FWI with crude initial models and to reconstruct meaningful subsurface velocity models. The good performance of the method, even considering the inaccurate amplitude prediction due to noise, imperfect modeling, and source wavelet estimation, bodes well for field data applications.