Jim Palmer returned to pitching eminence tonight and Eddie Murray hit his fourth major league grand slam home run to lead the Orioles to a 9-2 victory over the Cleveland Indians.

It was the second straight night for an Oriole grand slam and the crowd of 21,377, lured in part by a fireworks "sky concert" that followed the game, yelled its approval.

Round one of the fireworks came in the fifth inning, with the Orioles already leading, 3-0, behind Rick Dempsey's bases-empty homer in the third and his run-scoring single in the fourth.

Cleveland starter Rick Waits issued a fifth-inning walk to Lenn Sakata. Al Bumbry bunted for a single and Waits walked Rich Dauer to fill the bases with no one out.

Indian Manager Dave Garcia called on reliever Wayne Garland to face Ken Singleton, whom Waits already had struck out twice.

Garland walked Singleton, forcing in a run and bringing up Murray. The Orioles' switch-hitting first baseman, batting left-handed for the first time tonight, sent a picture-perfect fast ball into the 25th row of the right-field seats. It was a monumental homer, going high above the lip of the sky boxes. There was never a doubt where it would land, and Orioles were rounding the bases before it touched down.

Murray was four for five tonight, including a double. "I just hit the ball," he said. "I hit a fast ball for the grand slam. Waits fell behind, 2-0, so I figured he'd have to come with the fast ball.

"But on my double before that, I thought I hit a fast ball, until the guys told me it was a curve. So I knew it was going good when I didn't even know what I was hitting."

If the Orioles' new-found power at the plate was welcomed, an even dearer development was Palmer's return to respectability.

In his last two outings, he had been hit hard by California and Oakland and was 4-7 for the year.

The three-time Cy Young Award winner was complaning about shoulder and arm pain and it had been widely suggested that Palmer was washed up.

Tonight, he walked six and struck out only one in 7 1/3 innings, but when Manager Earl Weaver called for reliever Tippy Martinez, who retired the last four batters, Palmer had given up but four hits and two runs and all but secured his fifth victory.

Palmer hurried away after the game, but Weaver said the right-hander did not seem displeased at being lifted in the eighth. "Rather than have him reach back and hurt himself, I figured, 'Get him out of there and get him ready for Milwaukee.'

"The one good thing is, he's leaving the ball park healthy," Weaver said. "And that grand slam didn't hurt. I always say, 'A grand slam a day keeps the losing streaks away.' "

Palmer last won at Memorial Stadium on May 25. And in his two most recent starts he went a total of four innings and gave up 10 runs.

Catcher Dempsey, who broke a one-for-21 slump with his two hits, said Palmer made some simple mechanical changes in his delivery, which helped. He said that while Palmer was not overpowering tonight, "when he throws the ball like this, I know he's capable of coming back. At least he's aware he can change his game."

Dempsey said Palmer had been turning his back to the plate during his delivery. "I told him I didn't want to see his name (on the uniform). I aready know his name."

The win lifted Palmer's lifetime record against the Indians to 27-11 and gave the Orioles their 10th victory in the last 15 games. The Indians are on a tear of their own, having won 10 of 13.

Murray's grand slam was the fifth for the Orioles this season, all five coming in the second half of the season and in Memorial Stadium.

Lenn Sakata's four-run homer downed the Oakland A's Sunday and Sakata was back in the lineup at shortstop tonight. Sakata went two for three, with a double, and lifted his average to .500 (nine for 18) since he replaced Mark Belanger at shortstop.