Wayne B. Williams, under intensive cross-examination, held fast today to his version of events of May 22, 1981, when he was stopped for questioning after driving across a Chattahoochee River bridge.

Williams, accused of killing two young black Atlantans, testified that he was out at 3 a.m. that day hunting the address of a singer so he wouldn't get lost on the way to a scheduled interview at her apartment later that morning. But he denied police accounts that he turned around in a liquor store parking lot nearby, then drove back across the bridge.

"Could you be mistaken, Mr. Williams, or could you be lying?" assistant Fulton County prosecutor Jack Mallard asked.

"I'm on trial for my life, and I wouldn't be sitting up here and lying about something like that," Williams replied.

"Can you think of a better reason to lie?" asked Mallard, his voice dripping sarcasm.

"I haven't done nothing," Williams said. "I haven't killed nobody. I'm innocent, and that's all there is to it."

In parrying the prosecutor's thrusts, Williams came off his second day of testimony slightly wounded, but still a persuasive witness. Cross-examination is to continue Wednesday.

Williams, 23, is accused of strangling Nathaniel Cater, 27, and asphyxiating Jimmy Ray Payne, 21, two of 28 young blacks, and throwing their bodies in the river. The murders, over a period of two years, have been investigated by the FBI and a special task force here.

Two days after Williams was stopped near the bridge, Cater's nude body snagged about a mile downstream, near the spot where Payne's body had washed up a month earlier. Prosecutors also have been allowed to introduce evidence linking Williams to 10 other killings to show "pattern, scheme or bent of mind."

Williams maintained his composure as he fended off Mallard's rapid-fire questions, clearing his throat and sipping water from a yellow paper cup.

The square-jawed prosecutor read from a transcript of a June 4 news conference Williams called at his home after questioning by the FBI. In the transcript, Williams said he just happened to be "in the area" of suburban Cobb County and decided "to try and find her address since I was out."

But today, he said he had gone out specifically to locate a singer, Sheryl Johnson. "There's nothing inconsistent" in those statements, Williams said.

He demonstrated almost photographic recall for testimony, frequently challenging Mallard and denying any serious disputes with his father. But he stumbled when Mallard cited an interview Williams said he "vaguely" remembered granting Us magazine from his Fulton County Jail cell.

In the interview, Williams said his relationship with his father, a retired teacher, suffered severely after they argued and Wayne got drunk, "completely wasted."

Mallard questioned Williams about a possible connection between him and several victims whose autopsies produced wads of bubble gum. He said investigators had taken bubble-gum wrappers from Williams' wastebasket.

"You've heard that two or three victims had bubble gum in their bodies?" he asked.

Williams acknowledged that he had heard that, but denied such a connection.

Mallard asked if Williams was strong enough to lift 140 pounds, apparently referring to the approximate weight of Cater, one of the two victims whose bodies prosecutors say Williams tossed over the Chattahoochee bridge railing.

Williams said he had lifted weights in high school twice but that he considers himself a weakling. "I've lifted sleeping babies and children at night, and they're heavy," he said. Some spectators winced at the analogy.

Williams accused the FBI of holding him hostage in downtown Atlanta without access to an attorney after he was brought in for questioning last June. He said one agent yanked the telephone out of his hand as he tried to call a lawyer.

Again, Williams denied being a homosexual, or hating them, a partial motive police have suggested for the murders, even though he testified today that he referred to homosexuals as "Hostess cupcakes, gays, faggots and Twinkies."

"Doesn't a Twinkie mean a gay who is under 18 years old . . . ?" Mallard asked. Williams said he did not know. To him, a "Twinkie" was a "sissy," he said.

He denied knowing any of the victims, or the young black witnesses who testified earlier that Williams had propositioned them.

"You didn't offer Andrew Hayes $20 to commit sodomy?" Mallard asked.

"How could I, if I never met him?" Williams replied.

Williams fought off Mallard's attempt to portray him as a failed music promoter who hated ghetto youngsters and sought to purify his race by murdering them.

Instead, he remained polite and calm under fire as Mallard accused him of being a "dual personality, a Jekyll and Hyde." As he spoke those words, two black women jurors nodded.

Mallard demanded to know how Williams got scars on his arms, and accused him of strangling the victims with a choke hold. "Isn't it true while you were choking them, they were scratching at your arms and face with their last breath?" he asked.

"Absolutely not," said Williams, who said he got one scar from a kitchen grease burn and another from a fall while racing for the telephone.

"Did you experience any panic when you were killing them?" Mallard said, trying to rattle Williams.

"Sir," Williams replied calmly, "I haven't killed anyone. And I challenge you to find the scratches for the jury. I'm about as guilty as you are."

Williams denied animosity toward young blacks, and expressed sympathy for the victims and their families.

"I feel just as sorry for them as anyone in the world," he said. "I'm 23 years old, and I could have been one of those people killed out there. Anyone in Atlanta could be.

"And," he added, "I'm sure it's not over."