NEW YORK, FEB. 10 -- The invitation, printed in all modesty before he beat Sugar Ray Leonard into retirement, was to the post-fight party. It did not read "victory" party. The one-sided triumph over his idol was not going to change Terry Norris either.

One of his handlers jumped into the Madison Square Garden ring before the unanimous decision was announced.

"Damn it, Terry, you kicked his butt," said the exuberant handler.

Norris just shook his head.

"Please don't say that," he said. "Don't say bad things about Ray Leonard."

It was, he said, "a sad victory," having to beat up a hero. Now, at the post-fight party, the 23-year-old WBC junior middleweight champion was cornered. He was wearing blue jeans, a plain maroon shirt under a plain blue windbreaker, topped off by a black wool hat. The WBC championship belt fastened loosely around his waist hardly changed the blue-collar image.

He had the belt when he entered the ring to much booing from a disappointing crowd of 7,495 who had come to see Leonard open and close on Broadway in one night. But in the 12th and last round, the crowd was chanting, "Ter-ry, Ter-ry," and Norris would say later that the belt he had won 11 months ago with a first-round knockout of John "The Beast" Mugabi finally fit.

"I fought the best and now nobody can take it away from me," he said.

He also captured a baton Saturday night. If Leonard was going to lose, it was going to be to a worthy successor, a modest young man of considerable skill who had worked hard for five years to become the proverbial overnight success. Norris was planning a quick vacation to the Bahamas with his wife, but expected to be back training in two weeks.

"I'm a workaholic," he explained.

Norris, manager Joe Sayatovich and trainer Abel Sanchez endlessly studied videotapes of Leonard, saw how he often dragged back the left hand after throwing a jab. The left hand was low when Norris zipped a righthand over it in the seventh round for his second knockdown.

"Another thing we noticed," said Sayatovich, "was when Ray gets back on the ropes he'll slip sideways, always to his left. He'll have both hands down, but then he'll stop suddenly and fire a left hook, and that's his best punch.

"Most of the guys he's fought weren't quick enough to throw a right hand against him when he was open. If they tried, Ray would beat them to the punch. But like I said all along, Ray hasn't seen anything this fast since he was 24 years old and looking in a mirror. We had Terry practice taking a skip to the right and throwing the right hand. He must have nailed him like that a dozen times."

Norris's speed was the big edge. The fight was only a minute old when Leonard ducked a left hook, but then took three other rapid-fire punches.

"Ray couldn't believe it," said Sayatovich, who said he knew then for sure Norris would win. He turned to Sanchez and said, "Look at Ray's face, he's awestruck."

Norris has a dangerous habit of keeping his left hand low and Leonard did manage to land lead right hands often. But every time it appeared that Leonard might turn the tide, Norris retaliated.

"I had to gain Ray's respect," he said.

Maybe he had too much respect for Leonard, Sayatovich suggested. The manager believes in the late rounds his fighter didn't want to knock out his hero. "And backed off a couple of times."

"I had Lupe Aquino fight Duane Thomas for the vacant WBA junior middleweight title a few years ago and he was beating him over in Europe pretty easily," said Sayatovich. "In the 12th round, he dropped him again and the English referee helped Thomas up, talked to him, let him rest, and let the fight continue. Afterwards, I asked him what the hell that was all about. He said Thomas had taken such a beating and kept trying that he deserved to walk out of the ring. I couldn't argue with that. And that's what I think Terry was doing with Ray."

"No, no, I was just taking care of business," said Norris, insisting that Leonard was dangerous right to the end.

Even after his spectactular but controlled performance, Norris will find it difficult cashing in. There are no more Leonards against whom to make big purses. Sayatovich hopes one of the world's two welterweight champions, Simon Brown or Meldrick Taylor, would move up to give Norris another big bout. He would settle for a return to the Garden against one of the house fighters, former WBA welterweight champion Aaron Davis. The only big name in the 154-pound division now is Norris.

Boxing has been his only business. Leonard may have been his hero, but he was not his inspiration to enter the ring. His father had fought professionally and had taken his eldest son, Orlin Norris Jr., to Sayatovich's ranch in Campo, Calif. Terry followed when he was 18. For five years, he has been a full-time professional fighter. At first, he was in the shadow of his brother. Orlin Norris Jr., a ranked heavyweight returning from a career-threatening knee injury, stopped journeyman Jamie Howe on the undercard.

It took Terry two shots to win a title. In 1988, challenging Julian Jackson for the WBA version of the 154-pound championship, he had a huge first round, damaging both eyes of his opponent, fracturing a cheekbone and opening a cut on the lip that required 17 stitches. Cockily, he dropped his hands in the second round and Jackson, one of boxing's biggest punchers, knocked him out.

He learned from that experience. There was no lapsed concentration Saturday night. Leonard knew about the Jackson experience. Congratulating Norris, he counseled him: "You keep your focus and concentration, you'll be a great champion."

Norris's first loss, in 1987, was a 10-round decision to Derrick Kelly in a welterweight bout. It showed Sayatovich that Norris was too weak at 147 pounds.

Norris did repeat Saturday night a mistake that cost him the third loss on his 27-3 record. That was a one-round disqualification in 1987 against Joe Walker for hitting a fallen opponent. When he dropped Leonard in the second round with a left hook, he rushed over and took a swipe at him with the right hand. Leonard said he would have done the same thing.

A few years ago, he might have done a lot of the same things Norris did. But Saturday night, the dazzling speed and crisper punches belonged to the new kid on the block. He might be around awhile too.