Playing inspired basketball after forward Ralph Sampson was ejected from the game for fighting early in the second quarter, the Houston Rockets tonight ensured another weekend in New England for the NBA championship series with a 111-96 victory over the Boston Celtics tonight at the Summit.

Sampson was ejected with 9:40 left in the second quarter when, apparently angered by the defensive tactics of Boston guard Jerry Sichting, he punched first Sichting and then Dennis Johnson, precipitating a wild and lengthy melee that cleared both benches.

Houston, however, responded with its best basketball of the series. Dominating the middle after Sampson's departure, Akeem Olajuwon scored 32 points to lead Houston. The 7-foot center also had 14 rebounds and eight blocked shots in another brilliant effort as the Rockets cut the Celtics' lead in the best-of-seven series to 3-2.

Olajuwon's eight blocked shots tied the record for a championship series game set by Celtics reserve Bill Walton nine years ago, when he led the Portland Trail Blazers to the NBA title.

Boston's Kevin McHale led all scorers with 33 points and Larry Bird had 17. But they weren't nearly enough to prevent the necessity of a Game 6, which will be played Sunday afternoon at Boston Garden.

There, two big facts will be working against the underdog Rockets: The Celtics have won 40 consecutive home games, and no team has come back from a 3-1 deficit to win the NBA championship series.

If the Rockets win Sunday, Game 7 would be played Wednesday at Boston Garden.

Forward Rodney McCray had 17 points for Houston and guard Mitchell Wiggins, again coming in for struggling starter Lewis Lloyd, scored 16. Guard Robert Reid had 13 points and a career-high 17 assists.

"When we lost Ralph, we had to reach down deep and play like we had never played before," said Reid.

After the game, Sampson said of his teammates' effort: "They played a hell of a game without me.

"I'm sorry it happened," he said of the fight. "In an emotional game like that, a thing like that can happen. A foul should have been called on a Celtic . I did what I had to do. It was an unfortunate happening, but we're going back to Boston."

Jim Petersen, Sampson's replacement, contributed six points and 12 rebounds as the Rockets outrebounded the Celtics, 56-37.

"The ejection gave us a definite lift," the 6-foot-11 Petersen said. "We thought it was unfair. It was pretty much an even game before Ralph got thrown out."

The intensity of play exhibited at the start of tonight's game picked up where Boston's 106-103 Game 4 victory left off. Both squads seemed intent on establishing their fast break, although both struggled early before Boston took a 28-26 lead at the end of the first quarter.

Wiggins, who hit his first two field goal attempts in the first quarter after relieving Lloyd, hit another jumper 13 seconds into the second quarter to tie the game, but Bird responded with a three-point field goal less than 20 seconds later.

After baskets by Sampson and Walton, Olajuwon made consecutive baskets to put the Rockets ahead, 34-33.

At the 9:40 mark, an incredible melee broke out on the floor. In a mismatch situation, Sampson found himself being double-teamed by Walton and Sichting, who made do by grabbing the 7-foot-4 center. After trying unsuccessfully to free himself from the 6-1 guard's bear hug, Sampson responded by punching Sichting.

That led to the emptying of both benches, although no one was able to immediately control Sampson. Sampson also punched Dennis Johnson before being tackled by Walton, and the melee continued for several seconds.

After the floor was finally cleared, the Houston captain was given a technical foul and ejected from the game for fighting, Sichting being allowed to stay.

Johnson wound up with a cut alongside his left eye that needed treatment and returned to the game with a small bandage on the wound. Houston's Wiggins had blood on his uniform.

The sellout crowd of 16,016, angered by the decision of referees Jack Madden and Hugh Evans to eject Sampson but not Sichting, spurred the Rockets to a big lead after order was restored.

Some six seconds after play resumed, Boston was whistled for a turnover. But before Madden and Evans could retrieve the ball, the Celtics' Johnson had thrown it at the head of Petersen, who apparently provoked Johnson by attempting to grab the ball away from him after the whistle.

That resulted in another technical being called, this one on Johnson, and Reid converted to give the Rockets a 35-33 lead.

Perhaps inspired by the loss of Sampson (12 points, three rebounds), Houston went on to score another six points in the next 1:30 to take a 41-33 lead with eight minutes left before halftime and force the Celtics to spend a timeout to try to get a handle on things.

"Once the situation got out of hand between Ralph and Sichting, everything got out of sync," said Parish. "We forced it too much. After Ralph left, everybody took it upon themselves to win the game instead of the team as a whole."

Parish hit a pair of free throws at the 7:43 mark but the Rockets, now boiling, began to dominate the defensive boards, thus reaping results from their fast break.

The team went on an 11-6 run to move ahead by 52-41 with 3:44 left. The last basket was a powerful slam dunk by Petersen following an offensive rebound, a play that almost immediately led to another Boston timeout.

The next points came on a Wiggins jumper, but the Celtics quickly scored three points to make the score 54-44, Rockets, with 2:01 remaining in the half.

Danny Ainge hit three free throws for Boston -- one following a technical on Olajuwon -- and Boston closed to within 54-47. But Houston came back with baskets by Rodney McCray and Wiggins to take a 58-47 lead at halftime.

When the half ended, officials Madden and Evans were escorted off the court by about a dozen policemen as the capacity crowd booed.

Halftime did not slow down the Rockets' momentum. Led by Olajuwon's nine points, Houston outscored Boston by 28-18 in the third period, the first time in the series that the Celtics had been outscored in that quarter.

With three seconds left, guard Allen Leavell hit a three-pointer to give the Rockets an 86-65 lead as they closed the quarter with nine straight points.

Houston scored the first two baskets of the fourth quarter to take a 25-point lead, its largest of the game. The Celtics cut it to 98-85 midway through the period before falling back again as the Rockets kept the NBA season alive.

"We'll try and get that first game in Boston," said Reid. "Then we'll see what happens.