Former Louisville city councilman Hal Heiner conceded Kentucky's Republican primary for governor on Tuesday, but the race remained too close to call.

Heiner said he had called businessman Matt Bevin to congratulate him, though early returns showed Bevin in a virtual tie with Agriculture Commissioner James Comer. Former state Supreme Court Justice Will T. Scott lagged far behind.

Heiner urged his supporters to back the eventual nominee to get the governor's office back in GOP hands.

"While we are disappointed, I ask you to all stay involved. Support the Republican party," Heiner told about 100 supporters Monday. "It is time to move forward. Kentucky needs you, it needs your enthusiasm, your passion for good government."

Rumor-mongering and allegations that Comer abused an ex-girlfriend years ago marred the four-man race, and the mudslinging led him to declare it "the dirtiest campaign that I've ever witnessed in Kentucky history."

For his part, Comer denied the allegations and was never charged. He accused Heiner of scheming with a blogger who was promoting the abuse story.

Meanwhile, Bevin, a Louisville businessman who excites the party's more conservative wing, tried to rise above the fray, offering himself as an alternative to the nasty tension between Comer and Heiner.

Some voters appeared weary of the negative campaigning.

"I was so glad today came so we can stop watching the stupid ads on TV," said Doug McPherson, a Republican who said he voted for Scott because "I wasn't going to vote for those other three idiots."

The winner of the primary will take on the likely Democratic nominee Jack Conway in November.

The last time a Republican won the general election was in 2003, and then-Gov. Ernie Fletcher lost re-election to current Democratic Gov. Steve Beshear, who is term-limited.

Kentucky is the only Southern state where Republicans do not control the entire Legislature. Democrats have a slight edge in the state House.

The GOP campaign for governor intensified two weeks ago when Comer's ex-girlfriend Marilyn Thomas wrote a letter to the Courier-Journal accusing Comer of emotionally and physically abusing her when the two dated while attending Western Kentucky University in the early 1990s.

Ann Cobb, a Republican voter, was so put off by the negative campaigning that she still hadn't decided whom she would cast her ballot for when she arrived at a polling center Tuesday morning.

"It's been disgusting," Cobb said.

Heiner, who narrowly lost a 2010 race for mayor of Louisville, publicly apologized after the Lexington Herald-Leader revealed that his campaign had communicated with a blogger that had been pushing the abuse story on social media for months.

Things escalated Friday when Heiner, after vowing he would not mention the allegations, aired a TV ad based on them.

"There's certainly been some political turmoil over the last three weeks," Heiner said Monday. "But I believe the overriding concern, I hear it all the time, is that Kentucky is not where we can be. I believe when people go into the polls Tuesday and they decide to pull that lever, it will be based on that issue."

Comer and Heiner were seen as the early front-runners, based on Comer's status as the state's only Republican executive officeholder and Heiner's personal wealth that allowed him to outspend everyone on TV ads.

But Bevin, who was trounced by U.S. Sen. Mitch McConnell in last year's primary, has made a strong push in recent weeks. On Monday, he began airing a 60-second TV ad that touted his jobs plan and ends with: "I'm Matt Bevin, and I would be grateful for your vote."