Even before the opening tipoff today, Maurice Lucas was making all the class moves. For the most valid of reasons, anyone who cares deeply about sport was concerned that a ball game would develop into a brawl game. Such thoughts ended when Lucas was introduced and trotted the length of the floor of shake hands with Darryl Dawkins.

"Ever since it (the fight between him and Dawkins) happened all I saw was pictures of him and me squaring off - and him being made out to be a great gorilla," said Lucas. "Hey, he's a nice person, and things like that happen sometimes. I got no qualms against him.

"No. I didn't plan to go over to him. It just happened. I wanted to let him know I had no personal hard feelings. He didn't say anything. He didn't have to say anything. We understood each other."

And, after Lucas scored 27 points and the Trail-Blazers played two quarters of exquisite basketball for a 129-107 victory today, the Philadelphia 76ers understood their route to the NBA championship would be more difficult than they had imagained.

"You stop them from running their break," Trail Blazer coach Jack Ramsay had said 24 hours earlier, "you beat the 76ers." And the 76ers that had run Portland into submission at 78 r.p.m. were at a 33 1/3 pace today. Instead of a Concorde, Julius Erving was a Piper Cub. And George McGinnes never got off the ground.

Still, Ramsay gave his team all the credit - and properly so.Erving might be called The Doctor, but Ramsay has the doctorate - and he pu the game in marvelous perspective.

"When we play well, we can beat anybody," he said. "And today we played well. Or at least the first quarter and the last. The second quarter (when the 76ers narrowed what had been an 18-point deficit to one) we were fatigued, or something, and the third quarter was a holding action.

"There were absolutely no strategic differences. Our whole game is triggered by our defense. We need running and good ball movement to be effective - and today we got it for the first time in three games."

At times, though, the game seemed to be played four on four, with the 76ers' McGinnis rarely a factor and his prime sub, Steve Mix, chained to the bench. For the Blazer. Bob Gross was hampered by fouls and his reliever, Larry Steele, simply was gross.

When the Blazers put the game out of reach in the final nine minutes, though, it was Gross who started the blitz with a pass to Bill Walton and all but assured victory two minutes later with two drives on Dawkins.

"I think Bill got bumped by Dawkins when he put in that pass from Gross," guard Dave Twardzik said. "At least he seemed to be limping just about the time I got the ball after the in-bounds pass. Then all of a sudden he wasn't limping any more."

Walton was taking another high lob, this one from Twardzik, and slam-dunking the Blazers to an eight-point lead, 95-87, with 9:20 left. And the 76ers scored just 12 points in the next seven minutes. By then Gene Shue had conceded the game, substituting freely at the 6:10 mark.

But why the drastic turnaround, in both the Blazers and the 76ers?

"It is possible to play very well on another floor," Ramsay said. "We did it in Los Angeles and Denver. But it seems as though something happens on your home floor. Or it does for us.

"We were quicker today and Philadelphia was less quick. You determine what does that and a lot of people would like to know. I do know we play a lot on emotion - and our crowd helps us a lot."