In this paper, we pioneer a novel mechanism that jointly enforces intra-cell and inter-cell resource allocation for future green 5G networks. Our proposal, namely TOMRAN, efficiently coordinates the activity of base stations in small dense cell deployments by means of the ABSF standard tool for inter-cell interference coordination. Additionally, TOMRAN applies intra-cell offloading of the cellular traffic through resource-limited outband D2D relay communications, using, e.g., 802.11-based connectivity. We take advantage of this tailwind to show that our approach offers significant performance gain while imposing minor network protocol modifications. Indeed, through an exhaustive simulation campaign, we prove that outband D2D relay communications not only reduce the complexity of interference coordination operations, but also greatly boost the energy efficiency of future green 5G networks.