Incoming state Sen. Mike Bernskoetter, R-Jefferson City, won the vote in each of the 6th District's seven counties.
And Democrat Nicole Thompson placed second in each of the counties.
The final election returns still must be certified before they are considered official.
Secretary of State Jay Ashcroft's office announced Wednesday that certification is expected to be done by the state board of canvassers Nov. 30.
The unofficial returns showed Bernskoetter winning the state Senate race with 52,861 votes or 73.223 percent of all votes cast in the seven counties.
Thompson won 17,783 votes or 24.633 percent.
Libertarian Steven Wilson received 1,520 votes or 2.105 percent of the 72,192 votes cast.
Bernskoetter will take his Senate seat in January, when the Legislature begins its 2019 session.