We present here experimental results on the optimization of the mega-electronvolt ion source from the target front surface by using relativistic (10¹⁸ W/cm²) interactions with ultra-short laser pulses (50 fs). The source perturbation in the accelerated proton/ion beam was primarily controlled by the addition of a pre-pulse to main pulse contrast ratio. The 2D particle-in-cell simulations agreed well with the observed experimental results for the ion source perturbation and mitigation. This work provides insights into ion source perturbations (temporal and spatial) and the need to control them in intense laser–plasma interactions. Our results may assist in the efficient guiding of proton/ion beams to the core of fusion fuel or of ions in cancer therapy.