George Davis, incumbent local president of the largest union of Metro workers, was decisively, defeated in Wednesday night's runoff election by C. E. Boswell, who has never held union office.

Davis, who has been president since 1974, received 969 votes to Boswell's 2,196.

Members of Local 689 of the Amalgamated Transit Union also voted out secretary-treasurer Rodney Richmond, who held the office for four years. He lost to James A. Thomas, a driver from the Northern Division who got 1,910 votes to 1,034 for Richmond.

Defeat of the incumbents represents a shift to the leadership of the union that struck illegally for seven days in 1978. Metro's bus and rail employes have expressed anger on various occasions at both Metro and their union.

Union members have said that working conditions that caused the wildcat strike have changed little since the strike, and that the union does not represent the workers as effectively as many feel it should.

Specifically, union members say that the union has not enforced their rights to refuse to drive buses in poor mechanical condition, and that Metro supervisors do not snow enough sensitivity toward drivers.

Local 689 represents about 4,800 Metro bus drivers, train operators, station attendants and mechanics. The present union contract with Metro management expires April 30.