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 campaigned across 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 11-point lead with most ballots counted.
He now appears set to clinch the Republican nomination.
The former president last week won a landslide in Iowa's caucuses, with Ms Haley placing third, behind Florida Governor Ron DeSantis.
Mr DeSantis quit the race days later, leaving Ms Haley as the last remaining rival to Mr Trump.
At an election night party in Concord on Tuesday night, Ms Haley conceded the New Hampshire contest, 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, in a month's time.
"This race is far from over," Ms Haley said to a boisterous room of supporters. "There are dozens of states left to go. And the next one is my sweet state of South Carolina."
Even with her close ties to the state, opinion polls suggest Ms Haley is trailing Mr Trump by a wide margin.
Mr Trump did not seem to take well to Ms Haley's speech on Tuesday, calling her "delusional".
"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".
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, 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 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 - and experts said a loss in South Carolina's primary on 24 February 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.
Additional reporting by Kayla Epstein