Donald M. Fraser, a liberal former congressman, tonight easily won the Democratic-Farmer-Labor (DFL) primary for mayor.

Fraser, 55, defeated state Rep. James Rice, a longtime figure in state DFL politics and the closest of four opponents, by nearly 3 to 1.

Fraser's victory marked a comeback after his defeat last year in a bid for the U.S. Senate in a primary election that split the DFL.

Rice conceded just 13 minutes after the polls closed when a quick glance at returns from four key precincts, including his home precinct, showed him trailing.

At his headquarters, the often dour Fraser grinned and told the cheering crowd: "It is more fun to win than to lose," a reference to his defeat last year by conservative businessman Robert Short in the contest for the Senate seat vacated by the death of Hubert H. Humphrey. Short subsequently lost in November to Republican David Durenberger.

On the Republican side, Michael Barros, a political unknown, took an early lead in a field of four. The primary winners will face former "law and order" mayor Charles Stenvig in the November election. Stenvig, a political conservative who was mayor for six years, is running as an independent and therefore was not on today's primary ballot.

Fraser told reporters tonight he expected a tough campaign against Stenvig.

As a 16-year member of the U.S. House of Representatives, where he had a strongly liberal voting record, Fraser had always won easily in a congressional district that is largely coextensive with the city of Minneapolis.

Tonight he said that he had asked for a new vote of confidence and had gotten it. The voters, he said, had repudiated Rice's campaign. Rice's main attack on Fraser, notwithstanding Fraser's liberal reputation, was that the former congressman was the darling of the downtown big-business establishment.

Fraser contended that Rice's campaign amounted to "trying to start a class war in the city."