Segregation of liquid metal from solid silicate is a necessary pathway for core formation in a large rocky planetary body during the planet growth. The mechanism and extent of such process have an important effect on the geophysical and geochemical properties of the planetary body. Percolative flow of core forming melts through a silicate mantle has been ruled out as a possible mechanism of core formation by hydrostatic annealing experiments at pressures less than 50 GPa. However, an evolving mantle is not static, but continually deforming. Here, using element migration in the melts as an effective indicator for melt connectivity, we conclusively demonstrated that iron alloy melts could form an interconnected network in a solid bridgmanite matrix under deformation, even at a small total strain of ~0.1. Depending on the grain size of bridgmanite, percolation as a core formation mechanism could leave mantle disequilibrium/equilibrium with the core. The result showed that ~0.4 vol.% liquid metal was trapped in the silicate mantle and the stranded metal alloy could explain the highly siderophile elements (HSE) chondritic abundance in the Earth’s mantle without late veneer. Plain Language Summary We use element migration as an indicator of melt interconnection to demonstrate that core-forming melt can form an interconnected network in a bridgmanite matrix under deformation. The fast segregation velocity of melts in silicate makes the stress-induced percolation a feasible core formation mechanism. The melts left in the mantle after draining could explain the highly siderophile elements abundance in the Earth mantle.