SALT LAKE CITY (AP) _ Republican Robert Bennett and Democratic Rep. Wayne Owens were the winners in a free-spending primary election campaign for the U.S. Senate seat being vacated by Jake Garn.

Also Tuesday, Utah voters picked two first-time candidates, Republican Mike Leavitt and Democrat Stewart Hanson Jr., to fight it out for the governorship left open by two-term Republican Norm Bangerter's decision to return to his construction business.

The Senate primary campaign, featuring Owens and three millionaires, cost a combined $8.3 million, or nearly $22 for each vote cast. Industrialist Joe Cannon, who lost to Bennett 51 percent to 49 percent, spent $5.2 million, nearly $4 million out of his own pocket.

On the Democratic side, Owens defeated management consultant Douglas Anderson 61 percent to 39 percent.

The last time an incumbent wasn't running for the seat was 1974, when Bennett's father, Sen. Wallace F. Bennett, retired and Owens lost to Garn, a Republican.

''I think it's my turn,'' Owens said. ''I say that with a grin, but seriously, I think this state is ready for a Democratic senator.''

Utah hasn't had a Democratic senator since Orrin Hatch defeated Frank Moss in 1976.

Owens, 55, a four-term congressman, has lost in two previous tries for statewide office, his Senate bid in 1974 and to Bangerter for the governorship in 1984.

Bennett, 58, a former Washington lobbyist and businessman, campaigned as a political outsider determined to change Congress.

In the gubernatorial race, Leavitt, an insurance executive endorsed by Garn and Bangerter, defeated author and lecturer Richard Eyre 56 percent to 44 percent. Hanson, a former judge, received 57 percent of the vote to 43 percent for lawyer Pat Shea.