The GOP's nightmare scenario became a reality in Kansas on Election Night, where an insurgent Democratic newcomer toppled a Republican incumbent for the first time in nearly a century.

Megachurch pastor Adam Hamilton is projected to defeat first-term Sen. Roger Marshall, R-Kan., in one of the more unexpectedly close and brutal races during this midterm election cycle, according to Fox News Decision Desk.

Hamilton’s win in the Sunflower State marks the first time Kansans have sent a Democrat to the Senate since 1932. Marshall’s campaign sputtered in the late stages of the race, giving Hamilton an opening to peel off a large number of independent and rural voters — and it also served a bruising blow to Senate Republicans who are trying to cling to their slim majority in the upper chamber.

Democratic strategist Mally Smith told Fox News Digital that Adam Hamilton was the perfect candidate to run in Kansas.

"He was able to bring Republicans, Independents and Democrats together to pull a stunning upset. The combination of a blue environment, a scandal-plagued incumbent, and a strong Democrat like Hamilton made this upset possible," said Smith.

Though for months their race was not on the radar of national Democrats or Republicans, in the waning weeks Marshall acknowledged that he was running for his political life as headwinds battered Republican incumbents across the country.

"I think that, you know, I'm not a political expert, I'm a physician, but if we lose Kansas, I don't see how we keep control of the Senate," Marshall told Fox News Digital in an interview before the election.

"And that's why a vote for Adam Hamilton is a vote for Chuck Schumer and Democrat control of the Senate," he continued. "It’s that simple." But Hamilton has time and again said that he would not support Senate Minority Leader Chuck Schumer, D-N.Y., to continue leading Democrats if elected, a point he reminded Marshall of during their final debate.

"I’ve already said I wouldn't support Chuck Schumer for Senate majority leader if the Democrats took control of the Senate," Hamilton said.

Their contest morphed into a bitter, bloody battle that dragged in millions of dollars in resources and high-profile surrogates, like President Donald Trump, who rallied twice there weeks and days before the election.

It became dominated by brutal headlines against Marshall for his old medical practice, reportedly suing patients for unpaid bills, and searing ads against Hamilton that alleged he covered up sexual assault scandals at his church.

Kansas political experts argued that the race was ripe for Hamilton to take, given that he had a built-in popularity within the state fostered by his decades as the head pastor and founder of the largest United Methodist church in Kansas and the political headwinds created by Trump’s policies — Marshall for much of the campaign remained closely aligned with the president.

"I really just think it's entirely possible," University of Kansas political science professor Don Haider-Markel told Fox News Digital. "And if they can't do it this election cycle, I don't see when they're ever going to do it."