An A.C. relay system for making and breaking an A.C. power line utilizing an electromagnetic relay having a coil for opening and closing the mechanical switching contacts, a bilateral gated semiconductor such as a triac connected across the contacts, and a control circuit for switching the relay and triac in proper sequence is disclosed. The control circuit comprises a sequence control unit, a phase detector, a triac firing unit and a relay energizing unit. Upon actuation of the sequence control unit, the triac firing unit first fires the triac and then the relay energizing unit energizes the coil to close the mechanical contacts. To break the A.C. power line, the sequence control unit first de-energizes the relay energizing unit and then after a suitable time interval de-energizes the triac firing unit to cut off the gate signal, the triac being turned off when the load current on the power line is below a triac holding current.