World middleweight champion Marvin Hagler kept that title tonight, belaboring former champion Vito Antuofermo for four rounds and being awarded a fifth-round technical knockout.

Hager dominated throughout and was declared winner after Antuofermo, bleeding profusely from facial cuts, failed to answer the bell for round five.

Referee Davey Pearl said it was Antuofermo's corner, not he, that stopped the fight.

"I thought the fight could have continued," Pearl said later.

Antuofermo said he wanted to continue but his managers would not permit it.

Hagler, in a postfight press conference, said, "I wasn't looking to cut Antuofermo up. I was only looking to win.

"All I'm looking for is to show the people I'm a real champion and I'm going to be a champion for a long time."

Hagler, a left-hander with a 52-2-2 record and 43 knockouts, has developed a reputation as a cool, calculating and patient fighter and it showed in his handling of the man who fought him to a draw in November 1979 when Antuofermo was champion.

Attacking with an assortment of punishing punches and jabs, Hagler won every one of the four rounds on referee Pearl's score card.

"I scored it a shutout for Hagler," said Pearl.

Antuofermo, who has had chronic problems with cuts in fights in recent years, began bleeding profusely tonight 30 seconds into the first round. Pearl said later the cut was caused by a head butt, but that it was Antuofermo's own doing. "I told him so at the time and he seemed to accept it," Pearl said.

But at the end of the round, from Antuofermo's corner, Panama Lewis and Freddie Brown charged into the ring protesting vigorously to Pearl that in fact Hagler had committed a foul. r

Their protests delayed the start of the second round for about a minute and Pearl had the option of stopping the fight and declaring Hagler the winner.

"But I hate to do a thing like that in a championship," Pearl said.

In the next three rounds Hagler continued dominant, although Antuofermo fought back courageously, even after being knocked down by a savage left jab early in the third round.

Antuofermo, whose record slipped to 46-6-2, told the media he was butted twice by Hagler, in the first round and in the fourth when a cut was opened over his right cheek.

"It was bad enough getting butted the first round, but then he did it again. I didn't think the butting was that bad until I saw the replay on television."

Pearl said the second butting was caused by Hagler and that he warned the champion about it, threatening to take points away if it occurred again.

But Hagler said it was accidental. He was moving down for a body punch and his head collided with Antuofermo's.

"Those things happen," Hagler said.

Asked if he planned to continue fighting, Antuofermo, who has lost twice to former champion Alan Minter and has seriously considered retiring, said: "I'll have to think about it. I don't know. I'm going to talk to my doctor."

Hagler, cool and suave in a pinstriped suit at the postfight press conference, said he hopes to be matched with Sugar Ray Leonard or Tommy Hearns if they can come up to his weight classification.

A resident of nearby Brockton, home of 1950s heavyweight champion Rocky Marciano, Hagler fought professionally for nearly six years before he gained a championship shot and has been bitter that fighters he considered inferior gained title shots ahead of him.

His first opportunity was the bout that ended in a draw, permitting Antuofermo to retain the title; many believed that Hagler should have been declared the winner. Tonight marked Hagler's second defense since he took the crown from Minter last September.

A prelude to tonight's controversy came this afternoon at the weigh-in when the Massachusetts State Boxing Commission declared Hagler 160 pounds (to Antuofermo's 158 3/4) although the scales read 161 -- one pound over the middleweight maximum.Chairman Walter Byers claimed the scales had not been balanced in advance and the fight went on despite a threat by the Antuofermo camp to cancel. Earlier there was a dispute over the salve Brown uses on the oft-cut former champion.

In preliminary action, Washington middleweight Mike Baker scored a 10-round unanimous decision over southpaw Tony Chiaverini of Kansas City.