The New York Yankees and Baltimore played a lost classic in Memorial Stadium tonight, a hidden jewel of a drama won by the Yanks, 7-6, as they came from behind on a pinch-hit home run by Reggie Jackson and barely hung on against a ninth-inning Oriole rally.

Set on a grander stage than a raw April night in Baltimore before 16,721 stomping and shivering fans, this game might have been given birth to books, rather than the slimmest of volumes.

"Nothing is worse than a bad baseball game," said Oriole Manager Earl Weaver. "Iths a bigger gyp than a bad movie. But nothin' in the world is much better than a good one."

When the best Oriole hitter, Ken Singleton, saw his final foul pop blown onto the field of play by a stiff wind so that Graig Nettles, leaning against the third-base railing, could snag it, he smashed his bat at home plate.

The tying Oriole run died at third, the winning run at second on that last out.

This was the night for some of everything. Baltimore bashed the two Yankee aces-Ron Guidry and Goose Gossage-putting 15 runners on base against the G men. Only brilliant Yank defense, including three vital double plays, kept the Oriole lead to a mere 4-3 entering the eighth inning.

The world champions, according to habit, struck back as Jackson, benched against a southpaw starter, pinch-hit a two-run homer for a 5-4 New York lead. Nettles followed with a basesempty homer.

New York added an insurance run in the ninth-the basic thoroughness of champions-as Thurman Munson singled home Bucky Dent from third. Naturally, the Baltimore left fielder, John Lowenstein, missed a sliding catch by inches on the play.

The Orioles should have been beaten into submission by then. Everything had impeded them.

The Yanks had taken a 3-0 lead behind Guidry, entering an insurmountable margin for Louisiana Lightning.

The O's had answered with four runs in tha seventh as they chased Guidry on a Doug DeCinces homer and two walks, then tattooed Gossage with a double-single-double greeting.

Just when that outburst seemed to have turned the tide, Baltimore was punched in the solar plexus by amateur umpire Wayne Keister.

Rick Dempsey's double had scored one run to cut the New York lead to 3-2, then pinch hitter Lowenstein had singled in two for the 4-3 margin. Lowenstein took second on the throw to the plate, rounded the bag, and scampered back well ahead of Munson's peg to second.

But keister made as bad a call as any major league game will see, thumbing Lowenstein out. As Weaver threw a Grade A conniption, freezeframe instant replays were showing Lowenstein safe by three feet.

Al Bumbry, the next batter, doubled off the fence in left, a blow that would have scored Lowenstein.

Those here tonight will swear the final score was really 7-7.

"I'm just glad Ron Luciano didn't make that call," said Weaver, "because he would have gone home in a box.

"I guess I'm glad it was a fill-in ump who made a call that bad. If it had been Luciano or (Marty) Springstead (longtime Weaver enemies on the regular American League staff), you'd have been sure they nailed you.

"This was just a fantastic game. If we can score six runs off pitchers like this, and battle like this all year, a lot of people will be looking at our backs," added DeCinces, who now has an above-900 career slugging average against Guidry (22 total bases in 24 at-bats).

The O's ninth was a testament to their gumption.

Two walks and a swinging bunt single loaded the bases with one out off the mighty burner, Gossage. Bumbry slapped a single to center for one run. Mark Belanger's sacrifice fly plated another. Munson's passed ball with Singleton at the plate moved both runners into scoring position-each play turning the screw tighter.

Finally, after 2 hours 58 minutes of mounting tension, Singelton's pop hung over the box seats, then tantalizingly drifted back into play to the grasping Nettles.

Nettles was the right man to finish it all off.

He singled and scored the game's first run on Dent's triple off starter Scott McGregor. His RBI single followed a Chris Chambliss sacrifice fly an inning later to push the visitors' lead to 3-0. His long clout into the Yank bullpen off losing reliever Sammy Stewart in the eighth followed Jackson's vital two-run shot off Stewart that was barely fair in the leftfield corner.

Just as important, Nettles started two balletic double plays, stole a double from DeCinces with a dive over the foul line and a 360-degree pirouette, and robbed two other O's of singles with belly flops to his left. He was indeed the Magic Dragon tonight.

True to form, the Yankees muttered and mumbled their way to victory.

"Why didn't I start tonight?" groused Jackson. "The same old garbage as the last two years. . . They think I can't hit these Hall of Fame lefties like McGregor. Oh, I just sat in here and read a magazine," he joked.