In the Ohio Republican primary for Senate, ABC projects "Hillbilly Elegy” author J.D. Vance as the winner, marking a massive victory for former President Donald Trump.

Polling showed Vance fading into third place in the weeks leading up to the election, behind Mike Gibbons and Josh Mandel, but an eleventh-hour endorsement from the former president vaulted Vance into front-running status.

The "never-Trumper" turned Trump ally will face Democratic Rep. Tim Ryan in the fall.

Trump also endorsed former aide Max Miller in Ohio's 7th Congressional District. Miller was also projected to win his primary race on Tuesday.

Mike Gibbons, the wealthy Ohio businessman who previously ran for Senate in 2018, conceded over Twitter he would not win the GOP primary nomination for retiring Sen. Rob Portman's seat.

"We still don’t know who is going to win, but it is clear that we came up short. While tonight did not go as we had hoped, don’t be discouraged. We have a lot of work left to do. Tomorrow is the first day of the General Election- the most important election of our lives," Gibbons wrote in a tweet.

While Gibbons touted his ties to former President Donald Trump and his efforts to raise money for Trump's presidential campaign, he did not receive Trump's endorsement, while the candidate who did -- J.D. Vance -- has led the race all night.

In Ohio's 7th Congressional District, ABC News projects Max Miller as the winner of the Republican primary election.

The race represented a test of former President Donald Trump's kingmaking power after Trump threw his endorsement behind Miller, his former White House and campaign aide.

Miller was first vying for the seat of Rep. Anthony Gonzalez, a Republican who voted for Trump's second impeachment, until Gonzelez announced he was not running again after their district was redrawn. Before redistricting, Gonzalez represented Ohio’s 16th Congressional District.

Incumbent Rep. Bob Gibbs withdrew from the 7th District race after ballots were already printed, so any votes for Gibbs will not be counted.

Democratic Rep. Tim Ryan, a 10-term congressman, former presidential candidate and the son of union workers from northeast Ohio, celebrated his projected primary victory from Columbus on Tuesday.

"We’ve been to all 88 counties. Ninety-seven percent of our donations are under $100. This campaign is about the people of Ohio," Ryan told a room of supporters.

Ryan will face the winner of the GOP Senate primary race -- where Trump-endorsed candidate J.D. Vance is leading -- in an election that could help Democrats retain control of the Senate next year. A Democrat hasn't won a statewide race in Ohio since 2006 with one exception: Sen. Sherrod Brown's reelection in 2018.

Ryan told ABC News' Senior Washington Report Devin Dwyer Tuesday in his hometown of Warren that he is looking to replicate Brown's success by focusing relentlessly on jobs, wages, cutting taxes and cutting costs for families. He talked often about beating China -- and even mentioned policy areas he agreed with former President Donald Trump.

Even in this primary, he stumped regularly in red areas -- visiting all 88 counties.

Ryan said he likes to avoid the "stupid fights" and "culture war antics" of the "Trump knock-offs" he'll soon face.