Multi-channel medium access control (MAC) protocols have been developed to overcome the contention/collision problems that arise with single channel MAC protocols in ad-hoc wireless networks. In most of the currently available schemes, a single pre-assigned control channel carries all the control packets (RTS/CTS/RES) for data communication. One of the problems identified with this method is that as the number of nodes in a system increases, the throughput drops significantly due to heavy contention on the control channel. Moreover, even if several data channels are available in the system, many of them remain underutilized due to the unavailability of the control channel. This paper presents SU-MAC, a Smart Utilization MAC protocol, that assigns the available multi-channels dynamically. Our protocol combines the control and available data channel bandwidth to send control information and thus avoids blockage of the control channel for long periods. A power control scheme is also used as well to reduce interference and to effectively re-use the available bandwidth. Simulation results show that our SU-MAC protocol is promising in terms of reduced contention at the control channel and improved throughput because of channel re-use.