Despite one loser's accusation that he has become Chicago's newest boss, Mayor Harold Washington today savored an emphatic victory by his handpicked choice in Tuesday's crowded 1st Congressional District Democratic primary.

Veteran labor leader Charles Hayes, 65, who had never before sought public office, easiy captured the nomination to fill the unexpired portion of Washington's two-year House term that opened when Washington was elected Chicago mayor last spring. Hayes got 45 percent of the vote Tuesday in a field of 14 Democratic candidates. His nearest rival, broadcaster Lu Palmer, got 32 percent.

Hayes, vice president of the United Food and Commercial Workers Union, was backed by the mayor even though it was Palmer who organized the South Side voter registration drive upon which Washington fashioned his mayoral victory in April. Washington campaigned for Hayes, a longtime friend, and organized labor contributed thousands of dollars to an impressive Hayes campaign chest.

Palmer, who had led in most polls, assailed the mayor in a concession speech Tuesday night.

"I stood in awe at the sound and crunch of the wheels of a new machine and that machine rolled over us," he said. "The Washington machine really violated the principles of the movement which elected him."

Palmer called Washington the city's newest "boss" and refused to attend a unity brunch at which the mayor was host today.

Hayes seems assured of taking the congressional seat in the Aug. 23 special election. His opponent is a Republican and a minor party candidate in a district that is heavily Democratic.

The Hayes victory was especially pleasing to Washington, whose three months in office as Chicago's first black mayor have been marked by stalemate and controversy that has stalled his administration's reform moves.

He faces a white majority opposition in the City Council, and a stiff fight seems assured over his call this week for a $22 million tax increase and the firing of 569 city workers to help close what Washington says is a $59 million budget deficit.

A new controversy erupted today when the council majority voted to appeal a $600,000 court award in settlement of a race discrimination case brought by activist black policeman Renault Robinson against the city. Washington said he would veto the council's action.