MANCHESTER – Ovide Lamontagne, of Manchester, looked like he could be the giant killer Tuesday to beat U.S. Sen. Judd Gregg’s hand-picked successor Kelly Ayotte, of Nashua, and become the Senate Republican nominee to face Democratic congressman Paul Hodes, of Concord, this fall.

Lamontagne, 53, parlayed his long years in state politics with the desire of primary voters for an anti-establishment candidate to stun the critics and pundits who thought his low-money race would come up well short.

“You know, it’s amazing, we’ve led all night, and there’s no reason to believe we won’t end the night leading,” Lamontagne told an overflow and raucous rally at Jillian’s restaurant and billiard hall.

He may have spoken too soon.

By 12:30 a.m., Ayotte came from behind and took the narrowest of leads in the race, which was still far from over. With half of the state’s precincts reporting, Ayotte had gathered 29,786 votes to Lamontagne’s 29,567. Less than 220 votes separated the two.

“This election is one that will take a couple more hours tonight,” Ayotte said at the Grappone Conference in Center just before midnight today.

Ayotte, 42, a former attorney general, urged her supporters to keep the faith and believed the race could turn in the wee hours this morning.

“We’re getting numbers a little faster upstairs than television (in the ballroom) is showing, and this is a close election … We’ll be waiting and watching.”

At press time with 50 percent of the votes in, Bill Binnie, of Rye, and Jim Bender, of Hollis, were well back in third and fourth with 13 percent percent and 9 percent respectively.

The lesser-known candidates followed with Dennis Lamare of Lee with 1 percent, Tom Alciere, of Hudson, and Gerard Beloin, of New Boston, didn’t get enough votes to registed a percentage.

Hodes was unopposed in the Democratic primary.

With the Republican outcome still in the balance, Hodes said it didn’t matter if he faced Lamontagne or Ayotte.

“Whether it’s Mr. Lamontagne or Ms. Ayotte, it is an extreme, radical right-wing agenda that would take us back in time to the very same policies that got us into the hole that I am digging us out of,” Hodes said.

After spending nearly $6 million of his own money to finish third, a defiant Binnie said he’ll likely run for office in the future and keep fighting to make his party more inclusive to social moderates like himself who support abortion rights.

“The direction of the Republican Party is one of those issues we will debate, and I will argue for a bigger tent and a more inclusive party,” said Binnie, 52. “This is not a loss.”

Bender, 57, took an upbeat tone and urged supporters to keep their eyes on the ultimate prize in November.

“We have a lot to be grateful for, and what we need to do is rally behind our nominee and beat Paul Hodes,” Bender said.

Lamontagne came out of his hometown and surrounding towns with almost a 2-1 victory and a head of steam thanks in part to the New Hampshire Union Leader, which endorsed him and repeatedly discredited Binnie’s claim to be a creator of jobs.

Ayotte came back with more than a 1,000-vote victory in Nashua, but Lamontagne kept it close in places like Amherst, Concord and Bow and even beat her in towns Ayotte had to have, like Merrimack, Derry and Salem.

Gregg’s decision in March 2009 to not seek re-election and retire after 30 years in major public office resulted in a scramble of Republicans for the nomination.

The Democrats settled quickly with two-term congressman Hodes jumping in first. While others including fellow congresswoman Carol Shea-Porter and former state Securities Office Director Mark Connolly gave it some thought, no one else took the plunge.

For the first time in more than 50 years, none of the major Republican candidates who decided to run had been elected to anything.

Ironically, the only “elected” official was Alciere, who won a seat in the Statehouse a decade ago only to resign two months later over his online defense of killing cops.

Ayotte left her post 100 days after Gov. John Lynch renominated her to another four-year term. E-mails recently revealed Ayotte thought about the race within weeks of getting Lynch’s vote of confidence.

She quickly moved to line up establishment support starting with Gregg’s endorsement and extending to the previous two GOP governors, a majority of Republican legislators and all the county sheriffs.

Ayotte pulled off a daily double getting both sides of the 2008 presidential ticket behind her, Arizona Sen. John McCain hosting a Nashua town hall-style meeting and former Alaska Gov. Sarah Palin endorsing her on Facebook and doing a robocall for Ayotte in the final weekend.

But Lamontagne already knew how to come from way behind as he did in beating a better-known, better-financed foe in congressman Bill Zeliff in a 1996 primary for governor.

Gordon MacDonald, a longtime Lamontagne friend and supporter who worked on both races, said the magnitude of his possible upset overwhelms what happened 14 years earlier.

“This is unbelievable and much bigger than when Ovide beat Bill Zeliff,’’ MacDonald said.

“Kelly Ayotte had all the wind at her back and Ovide had to first jump over Binnie and then take her on. It’s amazing.’’

Months ago, Ayotte rolled out her vast team of prominent Republicans.

Meanwhile, Lamontagne waited to the final 10 days to air his first TV ad and announce big names rallying to his side from Senate Republican Leader Peter Bragdon of Milford and former Senate President Arthur Klemm of Windham to U.S. Sen. Jim DeMint, R-S.C. and Laura Ingraham of Fox News.

Former Manchester Mayor Emile Beaulieu said Lamontagne’s long work on conservative causes stood in contrast to Ayotte’s respected years as a non-partisan prosecutor and this paid big dividends.

“What you see from Ovide is what you get. He’s the same fine man and strong conservative he was 20 years ago,’’ Beaulieu said.

Pamela Lindberg served with Lamontagne on the state Board of Education under ex-Gov. Steve Merrill, who backed Ayotte.

“There’s an authenticity that comes through to people and it’s a big reason why as voters started really locking in on this race, he came across as someone who would be strong and could be trusted to be there,’’ Lindberg said.

Early on, Binnie invested $3 million of his money to purchase early TV/radio advertising and numerous mailers and promote himself as best equipped to help businesses recover from the sluggish economy.

By mid-July, polls showed Binnie had drawn even with Ayotte.

But Binnie’s support collapsed after former GOP state chairmen wrote an op-ed piece declaring Binnie too cozy in the past with Democrats and the socially conservative Cornerstone Action NH bought ads labeling Binnie a “liberal’’ for his views on gay rights, taxes and illegal immigration.

Binnie lashed out with attack ads against Ayotte on illegal immigration and gun owner rights while a supporter’s Federal Elections Commission complaint claimed without concrete evidence that Ayotte was in cahoots with Cornerstone Action.

When GOP State Chairman John H. Sununu sought a cease fire, Binnie shot back that it was “too late’’ and that Binnie was the victim.

After the Union Leader wrote a story concluding the plastics company he ran moved jobs from Southern California, Binnie bought a half-page ad to label the story “wrong’’ and demanded a retraction. The UL to this day stands by the report.

When Binnie’s attacks had clearly backfired, he shifted gears on the airwaves in the final week pulling his attack ads in favor of a direct appeal as a “social moderate’’ who supports legal abortion rights.

In the meantime, Lamontagne played the role of the patient tortoise, promoting himself with a 15-point Ovide’s Oath as the “only real conservative.’’

Outspent 6-1 by Ayotte and more than 10-1 by Binnie, Lamontagne built if not the biggest but surely the most deeply loyal network of supporters that looked like they would catch Ayotte at the tape.

Final polls over the weekend drew Lamontagne within 4 points of Ayotte who for weeks had been up by double digits over the rest of the field.

Bender took the high road throughout this primary, pointing to his career as an entrepreneurial fix-it artist who made more profitable the former, Logicraft Inc. in Nashua and other companies.

Staff writer Al McKeon contributed to this report. Kevin Landrigan can be reached at 321-7040 or klandrigan@nashuatelegraph.com.