It has long been held in NBA circles that usually there are two ways to defeat the Los Angeles Lakers, the defending champions and finalists in the past four league championship series.

One is to try to physically beat them, a tactic employed by the Boston Celtics the last two years and the Philadelphia 76ers the previous two.

The second method -- beating Los Angeles through superior athletic ability -- never really entered most coaches' minds. Playing against quality athletes such as Kareem Abdul-Jabbar, Magic Johnson, James Worthy, Michael Cooper and Byron Scott, that strategy didn't make that much sense.

However, following a 105-95 victory Sunday at the Summit, the Houston Rockets have taken a 3-1 lead in the best-of-seven Western Conference final by outplaying the Lakers at their own game. In the process, they have not only threatened to unseat the defending champions but also have dominated them.

"Before they had us backed to the wall," said Johnson. "If we don't come out and play on Wednesday they'll bury us."

Game 5 will be played at the Forum in Los Angeles Wednesday night, but to look at and listen to the Lakers, one wonders if it will be a mere formality. Last weekend in Houston, there was no effervescence on Johnson's face, no joy in his actions.

The same dour mien seemed to permeate the entire Los Angeles locker room after Sunday's game. There were assorted bruises, knees and fingers, not to mention a number of battered egos.

"It's been a long time since we've been in this position. We're not out, but they've got us reeling," said Abdul-Jabbar. "No matter what's happened, what adjustments we've made, they've done what they've had to do."

For the past four seasons, the Lakers have driven opponents dizzy with their dazzling fast break and their flexibility.

Was Cooper a guard or a small forward? Was that a guided missle or Worthy hurtling toward the basket? Was Larry Bird the only other player on the planet who could approximate the overall skills of Magic Johnson? In last season's championship series, the Lakers even found the muscle necessary to wrestle the championship away from Bird and the Celtics.

There definitely was not much opposition in the Western Conference, at least until now. The Rockets suffered a disappointing first-round loss to the Utah Jazz in last season's playoffs. This year, Houston had injuries to center Akeem Olajuwon and fellow skyscraper Ralph Sampson. In addition, guard John Lucas was permanently dismissed from the team for a recurring drug problem.

In its own way, however, each setback served to make this young Rockets team (30-year-old Robert Reid is the oldest player) better.

"We went through a couple of years where we were lost," said Reid. "I think it's the same thing the Lakers and Celtics had to go through. We kept our same personnel and added some spice to make things better. Now we're starting to peak."

Forward Rodney McCray, 6 feet 7, and Reid, 6-8, have kept Los Angeles off balance by triggering the Houston offense. Guards Lewis Lloyd and Mitchell Wiggins have taken turns disrupting the Lakers by playing bump and run with Johnson.

"That's the same old game as Philadelphia and Boston ," said Johnson. "They're doing more handchecking, but they've been able to because they've stopped us from getting out and running."

The question now being asked is whether the Rockets' rapid rise is an omen of things to come. Yet Houston Coach Bill Fitch said that even with his team's apparently commanding margin, "I fear the Lakers more now than after the first game a Lakers victory ."

But Fitch wasn't in the Lakers' locker room after Game 4. "We want to get back, but the Rockets want to get there, too," said Worthy, who scored 26 points. "I can remember how it was the first time I was here; I wondered what it was like to win a championship. They're a young and enthusiastic team."

Houston also has displayed more power. The Rockets have outrebounded the Lakers by an average of 47-37 and gone to the free throw line 122 times to 94 for the Lakers.

"They're playing us as well straight up as any team has ever played us," said Lakers Coach Pat Riley.

And what do the Rockets think of the Lakers' chances from here? "Fortunately I don't have to answer that," said Sampson. "That's what they have to think about, not us."