The Los Angeles Lakers, showing the fatigue of having played three games in five days, gave Philadelphia a scare today before fading as the 76ers won the opening game of the National Basketball Association championship series, 113-107, at the Spectrum.

The 76ers, rested and anxious after having completed their semifinal series against Milwaukee here Wednesday, got 27 points and 18 rebounds from Moses Malone; 20 points, 10 rebounds, nine assists and five blocked shots from Julius Erving, and 25 points from Andrew Toney. Despite that, they still needed 15 points and strong defense from reserve guard Clint Richardson and a little luck at the end.

The best-of-seven series will be resumed here Thursday.

The Lakers, defending champions, played a tough game at San Antonio Friday night to win the Western Conference title, then flew to Philadelphia late Saturday. They played today's game with virtually no preparation and without substitute Bob McAdoo, out with a pulled thigh muscle.

Nevertheless, they were in the game until the end in a wide-open, running affair.

The 76ers had 28 fast-break chances that they turned into 36 points, and the Lakers converted their 33 chances into 23 points.

"I don't care how tired we are, that's the way we play," said the Lakers' Magic Johnson. "We aren't going to change."

"That's what we expected from them," said Erving, "and we wanted to fight fire with fire. We didn't want to play half-court basketball if we didn't have to."

Lakers Coach Pat Riley said he was pleased with his team's effort, "especially when you consider it was our third game in 4 1/2 days. We'll be better Thursday, too, after we sit down and go over a few things. Sure, fatigue started to get us in the fourth quarter, but I'd much rather be here playing in Game 1 than back in Los Angeles playing San Antonio in a seventh game. I still feel good about our chances in this series."

With good reason.

The Lakers went into the final period trailing by two points, but they had lost a step. Quick baskets by Marc Iavaroni and Malone increased the lead to 89-83, and after five more points by Malone and six straight by Richardson, the 76ers had a 100-88 lead with 6:34 left.

But the Lakers kept running and shooting. Three baskets by Jamaal Wilkes and a Coop-a-loop lob dunk, with Michael Cooper scoring off a pass from Norm Nixon, got them within six. They scored on their next four possessions, but so did the 76ers, and they maintained a 111-105 lead with 71 seconds remaining.

Johnson, who finished with 19 points, 11 assists and nine rebounds, tapped in a missed sky hook by Kareem Abdul-Jabbar to cut the lead to four. The Lakers got the ball back when Maurice Cheeks' pass went three-quarters the length of the floor, over Bobby Jones' head and out of bounds with 21 seconds left.

Abdul-Jabbar missed another sky hook, though, and Johnson missed a follow. Jones rebounded and was fouled by Cooper. But Jones, who was suffering from strep throat, missed both free throws with 15 seconds to play.

Cooper missed a three-point attempt, however, and after Malone rebounded, Johnson fouled him.

Malone made his two shots to end the game.

"We were really tired, especially in the fourth quarter," said Abdul-Jabbar, "and we couldn't play our pressure defense the way we wanted to. We'll see how good we are Thursday."

"This is only one game," said Philadelphia Coach Billy Cunningham. "They (the Lakers) were tired coming in here and didn't have much time to get ready for us."

The first round of Malone versus Abdul-Jabbar went to Malone. Abdul-Jabbar finished with 20 points, but had only four rebounds. His sky hook was effective in the first half, as he made five of six shots, but in the second half he made only three of nine and missed the four hooks he attempted.

"It isn't an individual game between me and Kareem," said Malone. "I tried to get up close to him and take his hook away. I'm not going to block it, not unless he throws it from his hip. All I can do is push him out farther and try to make him take the jump shot instead. I need help from my teammates, too."

Abdul-Jabbar got plenty of help on Malone. In fact, Riley took him off Malone in long stretches and gave Mark Landsberger that assignment, freeing Abdul-Jabbar to roam.

Landsberger, a reserve forward, scored only four points, but had 10 rebounds in 19 minutes.

"Moses caused us some problems, but they aren't a one-man team, and that's what makes them so good," said Johnson. "But I'm not disappointed. We gave it our best effort. We just need to sit back, get some rest and get up for the next game."

Toney scored 15 points in the first quarter and the 76ers led, 30-20. With Johnson, Wilkes, Abdul-Jabbar and Cooper in foul trouble, Riley went to Landsberger, guard Clay Johnson and center Dwight Jones for much of the second period and that group helped the Lakers score 37 points and take a 57-54 lead.

Toney and Nixon collided in the first period and both had headaches the rest of the game. Nixon, who had 26 points, was taken to the hospital after the game; X-rays showed a bruised left shoulder, but he is expected to play Thursday. Toney, complaining of dizzy spells in the third period, was replaced by Richardson, who scored 10 points in the quarter.

Richardson tied the score at 64 with a base line jumper, and then three straight fast-break baskets, two by Cheeks and one by Erving, gave the 76ers a six-point lead. The Lakers could never catch up.