HILLSDALE, Mich. (AP)—An 18-year-old high school student said he was in shock Wednesday after being elected mayor by mounting a write-in campaign to oust the 51-year-old incumbent.

Michael Sessions had 732 votes to 668 for Mayor Doug Ingles, according to unofficial figures posted on the city’s Web site.

“It’s just a state of trying to believe it,’’ Sessions told the Hillsdale Daily News. “Especially that 732 people took the time to write my name in. My heart’s racing.’’

A cheer went up in the Sessions home when the results were announced over the radio. “I support him all the way,’’ said Scott Sessions, Michael’s father. “He has worked for it. He had the desire to do it.’’

Scott and Lorri Sessions at first had doubts about the wisdom of their son’s candidacy, the teen said.

“They thought I was crazy and (were) pretty skeptical of my campaign, but now they have smiles from cheek-to-cheek,’’ Sessions told The Blade of Toledo, Ohio.

Hillsdale, population 8,200, is home to the 160-year-old, 1,200-student Hillsdale College.

Pending clearance by the County Board of Canvassers on Thursday, Sessions will be the youngest mayor in city history.

Because the city’s electronic voting system counted all write-in ballots for Sessions, the only official write-in candidate, they will have to be manually reviewed and ballots that have other names or are illegible will be thrown out.

Sessions was 17 and not yet qualified to get on the ballot in the spring.

But one day after his birthday, on Sept. 22, he registered to vote. The next day, he signed up as a write-in candidate.

He used $700 from a summer job to fund his race.

“Right off, I’m not going to get their respect, they’ll say, ‘This kid could be my grandson,’’’ Sessions said of the City Council. “I’ve got to get acquainted with everyone first,’’ he said.

Sessions put up signs all over Hillsdale and campaigned door-to-door.

``It’s an honor to serve in the City of Hillsdale, and I’ll continue to work to make Hillsdale a better place,’’ he said.