ATLANTIC CITY, N.J., JAN. 23 -- The back of Larry Holmes' white robe carried the message in large red script: "This is it." As he stepped into the ring, his theme song played: "Ain't no stopping him now." Then, unfortunately for Holmes, the bell rang.

Mike Tyson came at Holmes with the same fury he did against every nobody he ever beat. By the fourth round, the 38-year-old Holmes was treated only to chin music -- a wicked right hand to the jaw by Tyson that started Holmes' downfall. This was it -- but for Tyson. Three knockdowns and Holmes was stopped cold at 2:55 of the fourth. "He's a true champion," said Holmes, when his head finally cleared late Friday night. And that's what the talk still was today along the Boardwalk:

"Did you see that punch?"

"Holmes didn't have a chance."

"Tyson's tough."

"He's better than I thought he was," admitted Holmes. "He's very hard to hit, and punches very good."

Tyson, 21, unscathed after 33 pro bouts, should have a long reign as heavyweight champion. "We're going to go around the world like we did with Muhammad Ali," said promoter Don King.

Tyson's tour begins March 21 in Japan against Tony Tubbs, if he's still willing after what happened to Holmes.

Tyson can gross $50 million this year, according to his co-manager, Bill Cayton -- and that's without a fight with Michael Spinks.

A meeting between Tyson and Spinks, also undefeated, will happen when Spinks' manager Butch Lewis bends to the will of Tyson's camp, which doesn't want Lewis to be part of the promotion. Cayton told United Press International today he is willing to make unspecified concessions to Lewis to get the negotiations started.

Spinks may call himself "the people's champion," but Tyson wears all three heavyweight championship belts when he climbs into the ring.

"We're ready to fight Michael Spinks," said an even-voiced Cayton, amid a postfight mob scene that included a smiling, silent Spinks and shrill cries from others for a Tyson-Spinks match. "The terms and conditions have to be set with Butch Lewis. When those can be set, we'll be eager to have that fight. It's as simple as that."

In the din, Tyson declared he would take on anyone, anywhere. No one doubted him after the onslaught Holmes endured. Tyson hit him at will, another case of an aging former champion who had overstayed his time. Holmes himself had done it to a 38-year-old Ali. Rocky Marciano had done it to Joe Louis.

Holmes had said he was going to "shock the world." He had said, "You've heard of these suicides among young people. After I whip Tyson, I hope he gets some bodyguards around him. They can stop him from a suicide. He might do it."

It was vicious, empty talk. Tyson is on his way; Holmes on his way home.

This morning, Holmes said he told his 5-year-old son Larry Jr. that he was finished fighting.

"My son said, 'I don't want you to quit, dad,' " Holmes told UPI. "I said, 'I quit, son. If you want to see me fight, come to the gym.' It was a good run, I hope nobody tops it for a while."

Tyson has a grand head start. A product of a Brooklyn ghetto who spent part of his youth in a school for juvenile delinquents, Tyson was blessed with his first stroke of fortune when the late boxing mastermind, Cus D'Amato, heard of him, sprung him and adopted him as a son. As King likes to say, "Only in America."

Tyson's career ignited. Beginning in March 1985, he knocked out his first 19 opponents -- 13 in the first round. On Aug. 1 of last year, he beat Tony Tucker to win the International Boxing Federation title. Added to the World Boxing Association and World Boxing Council titles he already had taken, Tyson had united the heavyweight championship. Now he had given Holmes, who had been heavyweight champion for more than seven years before his retirement 21 months ago, the same kind of whipping Holmes had given Ali.

Tyson had more than certified his punching power by the time Holmes hit the deck a third time, and stuck. Tyson toppled him the first time with a right, the second time with a barrage of lefts and rights and finally with another right that left Holmes motionless on his back for several seconds and off his feet for five minutes.

To Tyson, Holmes had been "a great fighter" but now he was just a "name." As Tyson saw it, "It's great to have the name on my record."

In the first two rounds, Holmes tried to frustrate Tyson by fending off blows and tying him up. But Tyson is maturing as a fighter. He may have rushed relentlessly at Holmes, but he did nothing foolish in the first six minutes, patiently waiting for an opening. "I'm too seasoned of a fighter at this stage of my life," he said, "to be frustrated."

In the third round, Holmes stepped up the tempo, circling and jabbing. It was what Tyson was waiting for -- so he could throw his right over the top of Holmes' jab. It was just a matter of time.

Time ran out for Holmes in the fourth. "I saw an opening and I took it," said Tyson. "I knew once I got him hurt he was finished."

It was emphatic. Dramatic. And pathetic, as the 6-foot-3 Holmes was stretched out for viewing by the screaming crowd of 16,000 in Convention Hall.

What more did he have to prove? Tyson asked. He hoped this ended any doubt that he is a worthy champion -- and could be a great one before he is through.

"I'm taking on all challengers," he said. "Everybody who was picking Holmes for an upset and saying I was the cheese champion, and for all the fighters out there who said Tyson wasn't all that good, just keep coming to the fights so you can take lessons."

The treasured heavyweight crown may not have changed heads Friday night but the torch was passed from one generation to another.

As King, self-described as "the baddest guy in the world," put it, Tyson had "demonstrated by action and deed that he could reach and touch someone and redirect that person's explosion energy to a more positive and constructive manner."

In other words, Tyson is the heavyweight of our time and Holmes was heading back to Easton, Pa., to resume a career in business.