<p>Magnetic-field-induced superconductivity is a rare property in nature because conventional Cooper pairs with spin-singlet symmetry are expected to be sensitive to perturbations that break time-reversal symmetry. However, in some cases, the interplay between finite magnetic fields and ions can be engineered to bring about superconductivity, despite the usual expectation. Here we demonstrate a magnetic-field-induced superconducting dome in a two-dimensional crystal of ultrathin LaSb₂ doped with dilute Ce paramagnetic impurities. The reduced dimensionality of the structure enables the use of an in-plane magnetic field to dynamically suppress spin fluctuations on the Ce site, and this leads to an anomalous enhancement of the critical temperature with increasing field. By modelling the spin scattering dynamics across the experimental parameter space, we gain insights into the complex nature of paramagnetic impurities in magnetic fields at low temperature and how their manipulation can result in the ability to tune between competing magnetic pair-breaking regimes. Demonstrating this effect in a two-dimensional crystalline setting invites the application of similar approaches to unconventional forms of superconductivity.</p>