John Kerr's goal a minute before halftime enabled the United States soccer team to tie Costa Rica, 1-1, today in an elimination game for the right to go to the 1986 World Cup soccer tournament.

The U.S. team leads Costa Rica by a point with the deciding match scheduled for May 31 in Torrance, Calif. Another tie would send the United States into a three-team tournament with Honduras and Canada for the right to represent the region in the World Cup.

"It was a difficult game," said U.S. Coach Alkis Panagoulias. "Costa Rica is a fine team. The race is still wide open."

Kerr, who attends Duke and was graduated in 1983 from Falls Church High School, scored for the United States in the 44th minute of the first half to calm down a noisy crowd that had celebrated a minute earlier when Costa Rica had scored.

During the playing of the U.S. national anthem, a group of Costa Ricans ran onto the field carrying a banner lettered: "Throw the military Yankees out of Costa Rica," an apparent reference to 20 military advisers sent to train the Costa Rican civil guard.

The crowd booed the protesters, who were removed by police, then demanded that the U.S. national anthem be played again.

Then the crowd chanted, "Gringos, gringos," and applauded.