Exhaustive search methods for optimum beamforming directions result in high computational complexity and increased time delays. Hence, this letter presents a novel initial beam discovery technique for codebook-based designs which leverages the presence of sidelobes as adjacent patterns to the main beamforming lobes. Namely, once a signal is detected in the direction of a sidelobe during beam scanning, the main lobe is shifted toward that direction and the scan is terminated. Simulation results show that the proposed scheme gives significant performance gains versus existing methods.