United States Democratic presidential candidate Hillary Clinton has won the South Carolina primary over rival Bernie Sanders, propelling her into next week's crucial "Super Tuesday" voting in 11 states on a wave of momentum.
With about a third of the votes counted on Saturday night, Clinton was easily winning with more than 75 percent.
"To South Carolina, to the volunteers at the heart of our campaign, to the supporters who power it: thank you," Clinton tweeted after major US networks all called the vote in her favour at the close of polls.
Huge cheers broke out at the venue in Columbia, South Carolina, where Clinton was due to deliver a victory speech to supporters.
"It's time, it's time, it's time for a woman in the White House," the crowd chanted.
Sanders immediately congratulated his rival, while vowing to fight on for the party's presidential nomination.
"This campaign is just beginning," he said in a statement.
"We won a decisive victory in New Hampshire. She won a decisive victory in South Carolina. Now it's on to Super Tuesday."
The win was Clinton's third victory in the first four Democratic contests, and solidified her status as the strong frontrunner to capture the party's nomination for the November 8 presidential election.
The former secretary of state's victory also established her strength among black voters, a crucial Democratic constituency who make up more than half of the party's primary electorate in South Carolina.
The result raised more questions about whether Sanders, the democratic socialist US senator from Vermont, will be able to compete away from his home base of Northeastern liberals.