Plasma drilling (hole boring) is one of the key issues in fast ignition of ICF fusion targets. Besides the methods by ponderomotive force or relativistic effects, we propose in this paper another possible route towards hole boring in the overdense plasma region via the explosion effect, which is a result of energy deposition when the suprathermal electrons generated by the ultra-intense laser pulse penetrate into the overdense region. Numerical results from a simple model are presented and the results show that more effective boring is possible by making use of the energy of suprathermal electrons.