Former Utah Democratic state lawmaker Jackie Biskupski will become Salt Lake City's first openly gay mayor after ousting a two-term incumbent in this month's vote, final election results showed on Tuesday.

Biskupski, 49, whose campaign touted her experience working in the private sector and law enforcement, defeated fellow Democrat Ralph Becker, a former colleague in the legislature of the socially conservative state.

Becker, who ran on his record of economic growth and clean energy plans, has been mayor of Utah's biggest city since 2008. Final results showed Biskupski taking 51.55 percent of the vote, versus 48.45 percent for Becker.

Biskupski thanked her supporters on social media and tweeted a photograph from a tree-planting ceremony held in Salt Lake City on Tuesday to honor its only previous female mayor, Democrat Deedee Corradini, who held office from 1992 to 2000.

"A wonderful way to celebrate this day," tweeted Biskupski, who previously worked in the auto insurance industry as well as the Salt Lake County Sheriff's Office and Unified Police Department.

She had been endorsed by the city's police and firefighters' associations before the Nov. 3 election. She takes office on Jan. 4.

Final election results on Tuesday also showed that Derek Kitchen, who is gay and a former plaintiff in a federal lawsuit that challenged a ban on gay marriages in Utah, won a seat on the Salt Lake City Council.

Utah's predominant faith, The Church of Jesus Christ of Latter-day Saints, opposes gaymarriage.

The Salt Lake City-based Mormon Church this year announced support for U.S. laws protectinggays and lesbians from discrimination in housing and employment. But its leaders have said sex should only happen between a wedded man and a woman and that they cannot endorse same-sex marriage.