Newt Gingrich has convincingly beaten Mitt Romney in South Carolina's primary election, the latest leg in the battle to be the Republican candidate in November's US presidential poll.
With almost all the votes counted, Mr Gingrich had 40% to Mr Romney's 28%.
Mr Romney was widely seen as the frontrunner, but the latest outcome is set to turn the race into a long, hard-fought campaign, correspondents say.
The South Carolina victor has won the nomination in each election since 1980.
The BBC reports that other Republican hopefuls, former Pennsylvania senator Rick Santorum and Texas representative Ron Paul are trailing badly, with 17% and 13% respectively.
The result means that three different candidates have won the first three contests so far.
Former Pennsylvania Senator Rick Santorum won the Iowa caucuses on 3 January and Mr Romney won the New Hampshire primary on 10 January.
Mr Romney slipped in the polls in recent days under criticism over his reluctance to release personal tax information.
The next contest on the calendar is the Florida primary on 31 January. It will be the largest state yet.
The BBC reports the economy is the top issue in this election, as President Barack Obama seeks a second term on 6 November amid voter frustration at the pace of recovery from the 2007 - 2009 recession.
Polling stations opened at 7am and closed at 5pm on Saturday.