NASHVILLE, Tenn. (AP) _ Two candidates in a down-to-the wire GOP primary for the right to challenge incumbent Democrat Sen. Albert Gore Jr. must wait after this weekend to find out the outcome of the election.

About 3,000 votes in Madison County will not be tabulated until Monday, said Madison County Registrar Spence Dupree.

''We're going to count it as soon as we can, but we've got every county position except for tax assessor to count first,'' Dupree said.

He said the county races would be tabulated first.

As late returns came in today, only 11 votes separated the two leading GOP contenders; so the Madison County votes could determine the winner.

With 2,293 of 2,415 precincts counted, or 95 percent, bankrupt businessman Ralph Brown led conservative political economist William Hawkins. Brown had 50,189 votes, and Hawkins 50,178 votes, or 39 percent for both.

In other races, the state's only black congressman crushed two Democratic challengers in his second re-election campaign conducted under the cloud of a federal bank-fraud indictment.

Gore, 42, ran unopposed for the Democratic berth and was expected to handle easily whichever Republican he faces in the Nov. 6 general election. He garnered 424,747 votes with 100 percent of the precincts in.

The 73-year-old Brown, who was forced to declare bankruptcy a year ago, didn't wait up for the results of his campaign, on which he spend less than $100. He turned in about midnight, said his wife of 50 years, Marie.

''He was very excited. But it got late. You don't know who won, do you?'' she asked a late-night caller.

Gov. Ned McWherter received 376,123 Democratic votes and will face Dwight Henry, a Republican freshman state lawmaker who suspended his campaign in June and resumed it less than a week before the election at the request of legislative colleagues.

Henry said: ''I don't think there's any question about who the David is in David vs. Goliath.''

U.S. Rep. Harold Ford defeated state Rep. Pam Gaia and Memphis businessman Mark Flanagan for the Democratic nomination. With 116 of 187 precincts counted, Ford had 28,380 votes, or 78 percent, to 6,946 votes, or 19 percent, for Gaia. Flanagan had 1,201 votes, or 3 percent.

Ford, 45, will face Republican Aaron C. Davis, a 79-year-old political newcomer, in the general election.

He was indicted by a federal grand jury in 1987 on bank and mail fraud charges. Jurors deadlocked in April after an 11-week trial. Prosecutors say a second trial will be held, but no date has been scheduled.

The eight-term congressman's backers have remained loyal. He contends the U.S. Justice Department targeted him for prosecution because he is a prominent black leader.

All nine of the state's congressional representatives are up for re- election, but only one beside Ford faced primary opponents.

U.S. Rep. Marilyn Lloyd, the state's only female member of Congress, defeated David Ray Stacy, a pipe fitter. Like Ford, she has been in Congress since 1975.

A three-way Republican primary in the Sixth Congressional District, which surrounds the Nashville area, included Jack Nugent, a white supremacist from Columbia who has gathered little support.

The seat is held by U.S. Rep. Bart Gordon, a Murfreesboro Democrat.