Elaine Marshall topped her biggest rivals, Cal Cunningham and Ken Lewis, in the primary for the Democratic nomination to face incumbent Richard Burr in the state's U.S. Senate race. But Cunningham said he planned to call for a runoff.

With 100 percent of the vote counted, Marshall won 36 percent of the vote, short of the 40 percent needed to avoid a runoff. Cunningham, the candidate backed by much of the party's leadership, had 27 percent, and Lewis got 17 percent.

In a speech to supporters in Lexington about 10:30 p.m., Cunningham said he believed he would defeat Marshall in a runoff vote.

"I told her that I hope we can continue to conduct this campaign in the same manner that we have so far," Cunningham said. "We will prevail June 22."

About the same time, Marshall was telling her supporters that she would be moving on to the general election to challenge Burr.

She praised Cunningham for running a "clean campaign."

"If Cal decides to continue to run this race for the next seven weeks, we'll beat him again with a larger margin than we did tonight," Marshall said.

Both had high praise for third place finisher Ken Lewis, whose endorsement would be a key for either campaign.

Both mentioned the fact that Burr was at a Washington fundraiser on election night rather than with North Carolina voters. A spokeswoman for Burr has pointed out that the Senate is in session this week.