The way newlywed Deborah Fuller recalls it, "The whole wedding day was perfect," until a crowd of rowdy youths showed up, quickly and without warning, brandishing chains and calling out racial epithets.

Mrs. Fuller, 22, a secretary with Computer Sciences Corp., and James M. Fuller, 24, senior assistant manager for Household Finance, were married last Saturday afternoon at a Baileys Crossroads church. The couple had a wedding reception at the church, and had rented a room for a party and discotheque dancing that night for their young friends.

The dancing was to be in the party room at Brighton Square Apartments, at 4817 Monitoba Dr. in Fairfax County, south of Alexandria. Fuller lived in an apartment in the Brighton Square complex, and the newlyweds said they had planned to make it their home.

But at about 8:45 Saturday night, as 20 relatives and friends were helping the Fullers, who are black, prepare the room for the party, some white youths approached the door and began pounding on it, calling out names like "nigger" and "blackie." Fuller said.

The youths, about 25 of them, apparently had come to the party room thinking a teen center affair was being held, according to Fairfax police and apartment manager Marie Del gordi.

"It was a mess," Fuller said yesterday. He said one youth used a numchaku -- a martial arts weapon consisting of two short pieces of oak linked with chain -- to break out a window, but the youths were unable to get inside the room. The party had to be cancelled, however.

Fairfax County Police Officer Raymond Kohler said he arrived at the party room at about 9:30 p.m.

"At that point, we were there to keep everybody separated," Kohler said. "We stood by until Fuller was able to move all his guests out of the building. The blacks were very orderly. They were there for a wedding reception, not a brawl. The juveniles thought it was a teen center, and when they found a reception, they apparently started an unfortunate incident."

Kohler said one youth, William Q. Williams, 19, of Evergreen Lane in Annandale, was arrested and charged with disorderly conduct. Kohler said the case is still under investigation.

Kohler added, "We get a lot of problems with juveniles in that area. They create minor disturbances."

Mrs. DelSordi, Brighton Square manager, said that the tenant civic association uses the party room on weekends for a teen center if there is no scheduled event. She said that when she inspected the party room yesterday, she saw no damage to the room from Saturday night.

Joseph Wharton, property manager of Lerner Corp., which owns Brighton Square, called Saturday's incident "minor, apparently some youths trying to crash a party." Brighton Square's problem with juveniles is "nothing worse" than other apartments projects are experiencing, he said.

But the Fullers said yesterday they were frightened by the incident. Their wedding party was ruined, they wasted $225 on a disc jockey who didn't get a chance to spin records, their food spoiled, and they spent their wedding night in a hotel because they were afraid to go back to Fuller's apartment.

Yesterday was the start of their honeymoon trip to Ocean City and Virginia Beach. Instead, they said they will spend the week looking for a new apartment.