= The evolutionary impact of crop-to-wild gene flow depends on the fitness of hybrids under natural, competitive conditions. Here, we measured the performance of third-generation radish hybrids (Raphanus raphanistrum +Raphanus sativus) and weedy R. raphanistrum to understand how competitive interactions affect life history and relative fecundity. #NAME? semi-natural, agricultural conditions in Michigan, USA. The effects of competition on life-history traits and fecundity of F3 progeny were measured 2 yr later in a common garden experiment. #NAME? fewer fruits per flower than wild plants, resulting in lower lifetime fecundity. With increasing competition, age at reproduction was delayed, the relative number of seeds per fruit was reduced in wild plants and differences between hybrid and wild fecundity diminished. #NAME? to wild plants by reducing differences in life history, potentially promoting the introgression of crop alleles into weed populations.