Republican presidential hopeful Nikki Haley has vowed to press on with her campaign in the wake of a second consecutive loss to Donald Trump.
Ms Haley toured much of New Hampshire ahead of Tuesday's primary, courting both independent and moderate Republican voters.
But she was unable to catch Mr Trump, who had a comfortable 10-point lead with most ballots counted.
The former president last week won a landslide in Iowa's caucuses.
Days later, Ms Haley became the last remaining rival to Mr Trump, with the sudden departure of Florida Governor Ron DeSantis from the Republican field.
At an election night party in Concord on Tuesday night, Ms Haley conceded the New Hampshire race, congratulating Mr Trump on his win.
But she vowed to take her bid to become the Republican party's presidential candidate back home to South Carolina, the state where she served as governor.
"New Hampshire is first in the nation," Ms Haley said to a boisterous room of supporters. "It is not the last in the nation.
"This race is far from over. There are dozens of states left to go. And the next one is my sweet state of South Carolina."
Mr Trump did not seem to take well to the speech, calling her "delusional" at his own election night party. "Who the hell was that imposter that went up on that stage that went before and claimed victory?" he said.
Team Haley hit back almost immediately, describing his speech as a "furious and rumbling rant".
"If Mr Trump is in such good shape, why is he so angry?" the campaign said in a statement.
For months, Ms Haley remained cautious in her criticism of Mr Trump, the prohibitive frontrunner and her former boss.
But in New Hampshire last weekend, as she campaigned through her 52nd birthday, the former UN ambassador made her most pointed attacks to date, warning of his friendships with "dictators", questioning his mental acuity and slamming his "lies".
Exit polls from CBS News, the BBC's US partner, showed her 11th-hour sprint may have paid off - two-thirds of voters who made their decision in the last few days voted for her. And Ms Haley outperformed opinion polls that had shown her trailing Mr Trump by around 20 points.
Still, despite the Granite State's sizable bloc of independent voters - those who were considered likely to favour Ms Haley - she could not fully close the considerable ground between herself and the former president.
"Nikki put in the time, put in the work and put in the money," said Katon Dawson, a Haley surrogate and the former chairman of the South Carolina Republican party. "With that said, Donald Trump is an 800 pound gorilla that has his arms around the base."
Across New Hampshire ahead of the primary, some members of that base told the BBC they thought Ms Haley was insufficiently conservative. Others said they liked her personally, but that they would not waver in their support for Mr Trump.
"I'm not sure about some of her policies," said Pat Hansen on Tuesday in Manchester. And it reflected poorly on Ms Haley, she believed, that top Republicans in South Carolina had turned their backs on her and endorsed Mr Trump.
Ms Haley is opting out of the third Republican contest - caucuses in Nevada - meaning her next major match-up with Mr Trump is several weeks away, in South Carolina's primary on 24 February.
There, she hopes to be welcomed by a loyal base of voters who twice sent her to the governor's mansion.
"She's got a track record here," said Bill Nettles, a Democrat who served as a top prosecutor in the state while Ms Haley was governor. "She left office very popular."
But even with her close ties to the state, opinion polls show Ms Haley trailing Mr Trump by 30-plus points.
Experts said a loss in her political backyard would likely be fatal to her campaign.
"The momentum is moving toward Trump rapidly and he's likely going to close the nomination early," said veteran Republican strategist Ron Bonjean. "There's little doubt now."
And there's this daunting piece of political trivia for Ms Haley: no Republican candidate has ever won the first two states and not gone on to become the Republican nominee.