Incumbent Democrat Robert T. Reives II, of Sanford, easily defeated Republican challenger Andy Wilkie, of Goldston, on Tuesday.
He received more than 56 percent of the vote, to Wilkie's nearly 44 percent.
Reives, 44, was appointed this year to replace Deb McManus, who resigned after being arrested on felony tax charges. Reives listed education, the environment, women's health and voting rights as priorities.
Wilkie's platform emphasized agriculture and voter-identification requirements.