Incumbent Lonnie Laffen, a Republican, lost his North Dakota Senate seat Tuesday to JoNell Bakke, a Democrat, in the race to represent District 43.
Bakke drew 53 percent of the vote, while Laffen attracted 47 percent.
For the North Dakota House, Democrats Mary Adams and Matt Eidson defeated Republicans Ben Olson and incumbent Richard Becker.
Adams captured 28 percent of the vote, while Eidson won 25 percent. Olson received 24 percent and Becker 23 percent.
Election results are preliminary and unofficial.
District 43 covers southwest Grand Forks.
Bakke, who served in the Senate from 2007 to 2011, is a retired special education teacher who works at UND, supervising student teachers.
The most important issue facing the state is balancing the budget, she said. She also wants to make child care more accessible, so that more people can enter the workforce.
Bakke replaces Laffen, a founder of JLG Architects, who has represented District 43 in the Senate since 2011.
Adams, a real estate agent, has said she's most concerned about helping teachers, the poor and elderly.
Eidson, a full-time student at UND, has said he wants to propose an incentive program that would encourage veterans to stay and work in the state for two years after earning an aviation degree at UND which would strengthen the unmanned aerial systems industry and bolster the state's economy.
Incumbent Becker completed his first four-year term in the North Dakota House.
Olson, a real estate agent, ran as a first-time candidate for the House.