Nature is replete with a form of omnivory called intraguild predation (IGP), wherein an IG predator competes with its IG prey for a shared resource. Original theory predicted limited regions of coexistence, dependent on a tradeoff between competition and predation that occurs only at intermediate levels of resource productivity. However, evidence shows that natural food webs contain intraguild predation with frequencies up to 87%, creating a discrepancy between original IGP theory and empirical evidence in nature. Much theory has been developed to mend this discrepancy, altering key assumptions and investigating stabilizing mechanisms of IGP. This theory, however, has largely gone untested, resulting in a stark disconnect between theory and empiricism. In this dissertation, I bridge IGP theory and empiricism by developing and explicitly testing theory regarding stabilizing mechanisms of IGP dynamics. In the following chapters, I explore three theoretically-investigated stabilizing mechanisms: adaptive foraging, cannibalism, and spatial resource heterogeneity. First, I use mathematical modeling, including Lotka Volterra and Rosenweig-MacArthur models adapted to IGP systems, to develop new theory. Second, I use protist microcosm experiments, which allow for explicit integration of theory and empiricism, to test new and existing theory. I find that adaptive foraging, cannibalism, and spatial resource heterogeneity are all significant mechanisms that stabilize IGP dynamics, enhancing stable coexistence of IG predator and IG prey across a range of environmental conditions. First, adaptive foraging in the IG predator allows IG prey to rebound from densities close to zero, preventing IG prey exclusion. Second, preferential cannibalism in the IG predator serves as an important density-dependent population regulation factor, preventing both overexploitation and competitive exclusion of the IG prey when the IG predator is a strong resource competitor. Third, spatial resource heterogeneity promotes rescue effects that greatly enhance both regional and local coexistence in habitats that are otherwise suboptimal to the IG predator and/or IG prey. This dissertation fills an important gap in the literature that is the disconnect between theory and empiricism of one of the most ubiquitous species interactions, intraguild predation. These studies collectively reveal the biological importance of key generalizable mechanisms that stabilize this interaction.