In cluster-based multihop networks, the Ad Hoc Routing (AHR) scheme has been proposed to reduce the implementation complexity of the optimal routing scheme. However, this complexity reduction also causes performance loss. In addition, when the practical distributed relay selection is considered, further performance loss occurs due to the relay selection error. In this paper, we exploit cooperative diversity to compensate these performance losses, address the problem of the conventional distributed relay selection scheme, and then propose a novel Distributed Ad Hoc Cooperative Routing (DAHCR) scheme. In the proposed approach, the sender selects not only the receiver but also one relay to form a cooperative communication to reduce the power consumption. Simulation results reveal that the performance improvements achieved by the cooperative diversity and the proposed DAHCR scheme are the trade-offs of increased complexity.