NEWARK, Ohio - The special election for Ohio's 12th Congressional District came down to the wire Tuesday night, with Republican Troy Balderson edging out Democrat Danny O'Connor in unofficial results.

With 100 percent of precincts reporting, Balderson had a 1,754-vote lead over O'Connor, with more than 202,000 votes cast. Green Party nominee Joe Manchik had a little more than 1,100 votes, or about 0.6 percent of the vote.

O'Connor declined to concede the race Tuesday night, telling supporters "We're not stopping now!" News outlets, including the Associated Press, also did not call the race, citing the number of uncounted absentee and provisional ballots.

There are 5,048 outstanding absentee ballots and 3,435 outstanding provisional ballots left to count, according to the Ohio secretary of state's office.

However, Balderson and other Republicans claimed victory late Tuesday night.

"Tonight, I'm going to promise to you that I'm going to work relentlessly - relentlessly for this 12th Congressional District," Balderson told a crowd of cheering supporters. "America is on the right path, and we're going to keep it going that way."

Democrats had hoped to flip the reliably Republican Central Ohio seat, which opened up when Republican Pat Tiberi stepped down in January. While President Donald Trump won the affluent, well-educated district by 11 percentage points in 2016, the president's ratings in the district have dropped in recent polls.

But Balderson, a state senator from Zanesville, scored a 22-percentage-point win in GOP-friendly Licking County and a 9-point victory margin in conservative Delaware County. O'Connor, the Franklin County recorder, won his home county by a landslide, but Balderson won the other six counties in the district.

Balderson, who also won a crowded GOP primary in May by a razor-thin margin, relied on outside groups for most of his ads - most notably the House GOP-linked Congressional Leadership Fund, which poured millions into ads claiming that O'Connor would support GOP bete noire Nancy Pelosi for House speaker. (O'Connor pledged early in the campaign not to back Pelosi for speaker, though he grudgingly yielded to MSNBC's Chris Matthews that he would support her over a Republican speaker).

Balderson also drew last-minute help from President Donald Trump and Vice President Mike Pence, both of whom campaigned for Balderson in the final days of the race.

O'Connor, meanwhile, raised nearly $1.5 million - most of which was spent on ads portraying him as a moderate and hitting Balderson for saying he would be open to raising the minimum age for Social Security and Medicare.

Even with a loss, O'Connor's performance in a traditionally Republican district may give hope to Democrats that he can beat Balderson when the two clash again in a contest for a full, two-year term in the November general election.

But U.S. Rep. Steve Stivers, the chair of the National Republican Congressional Committee, told cleveland.com Tuesday night that "a win's a win" for Balderson.

"Democrats, I'm sure, are going to try and turn this into some sort of moral victory," Stivers said. "But last time I checked, moral victories don't get a vote on the congressional floor."

Cleveland.com politics reporter Seth A. Richardson contributed to this story.