Republican presidential front-runner Mitt Romney has scored a narrow win in Maine's caucuses.
Results of Maine's poll showed the former Massachusetts governor with 39% support, or 2190 votes, ahead of libertarian Texas Congressman Ron Paul with 36% or 1996 votes.
Former US Senator Rick Santorum and Newt Gingrich, the former speaker of the US House of Representatives, who did not campaign in Maine, won 18% and 6% of the vote, respectively.
Despite anecdotal signs of higher voter turnout, the votes cast in Maine were only slightly above 2008 levels.
A handful of communities have yet to hold their caucuses.
The Maine outcome capped a good day for Mr Romney, who unexpectedly lost to Mr Santorum, a social conservative, in Missouri, Minnesota and Colorado on Tuesday to generate new doubts about his appeal to party conservatives.
Republicans are seeking a nominee to challenge Democratic President Barack Obama in the 6 November general election.
Some 21 delegates will be allocated from Maine.
A candidate needs 1144 delegates to clinch the Republican nomination.
More moderate than his rivals, Mr Romney, a former venture capitalist, has struggled to convince conservatives he is one of them.
Mr Romney topped a straw poll at the Conservative Political Action Conference (CPAC) in Washington, with 38% support to Mr Santorum's 31%.
He spoke CPAC on Friday and called himself "severely conservative."
"I'm committed to turning around America. And I'm heartened to have the support of so many good people in this great state," Mr Romney said in a statement after the Maine results.