This was a night for standing O's.

The O's in question were the Baltimore Orioles, who took turns this evening stepping out of their dugout to make curtain calls and take bows for their dynamic work in a 10-1 lambasting of the New York Yankees and Rod Guidry.

Doug DeCinces earned his standing ovation from the 42,949 fans in Memorial Stadium with two long homers into the Baltimore bullpen and five RBI. A third DeCinces rocket with two men on was caught by a jumping Oscar Gamble six inches from the top of the left field fence.

Another Oriole worth cheering was Jim Palmer, the future Hall of Famer and self-proclaimed has-been, who pitched a corner-nipping five-hitter in which only two Yankees got past first base, the only one who mattered being Reggie Jackson, who hit a 450-foot home run.

"Don't fall for that hokie-dokie about how he's getting old," said Jackson. "Jim Palmer is still a great pitcher. After he got that lead, he just played with us, teased us, made fools out of us. He's got every pitch and he threw them to every spot. It was takeover time and the man took charge."

Despite the O's dozen hits, including three for three and two RBI by Bennie Ayala, the loudest ovation came for the most unlikely Bird -- Mark Belanger.

It was Belanger, hitting .161, who transformed this game into a rout with his titanic -- yes, titanic -- solo home run off Guidry in the second inning that crashed against the top of the left field foul pole at upper deck level.

When Belanger swung, the Bird lead was a mere 3-1. Even after Belanger had chugged around the bases in a head-down sprint, then had been called out of the dugout twice by applause -- once for a sheepish tip of the hat and once for a full, lingerting bow -- the score was 4-1.

But on a night when Belanger hits his first homer in 393 games, 939 at bats and nearly four years, there's no way his team's going to lose.

"I got all of that one," Belanger was heard to say repeatedly as he bounced all over the dugout, unable to sit down because of his excitement.

The mighty Belanger, who also made his customary hit-robbing defensive play for the night at shortstop, has not hit a homer since Sept. 5, 1977, and had not connected in Memorial Stadium since June 21, 1976 off Luis Tiant.

"I only hit homers off brand name pitchers," said Belanger, the epitome of bored savoir-faire after the game.

What pitch did he hit?

"A slider . . . I think."

Did he watch his mighty poke -- of which Palmer generously said, "Frank Robinson's the only guy I ever say go that high up on the pole?"

"I don't think about those things," said Belanger. "I just start running.

"I don't think I've ever had a standing ovation for an offensive play before."

By the late innings, as a certain cab driver led the "O-R-I-O-L-E-S" cheer atop the dugout, half the Baltimore team was on its dugout steps watching the crowd go nuts and soaking up the ambiance.

The Birds of Baltimore have simmered for more than six months since their great comeback of 1980 left them three games shy of the division-winning Yankees. Between these two teams -- the AL champ O's of 1979 and the Yanks who have won four of the last five division flags -- there is an immense unanswered question: which is better?

The Orioles, who dawdled for two months last season, atoned for that sin with their fast start tonight. The Yankees, who made three errors and looked listless all night, had a closed door team meeting called after the game by annoyed Manager Gene Michael. "I said a few things," he said, "which I won't repeat. We have to do some things differently."

Presumably, he meant that Guidry could not give up seven runs in fewer than fire innings; even the outs off Louisiana Lightning were smoked. Guidry, after this game, confirmed that he has a chronic bruise on the ball of his right foot where he slams his lead leg down hard as he drives off the mound. What causes it? "Pitching," said Guidry. What would heal it?"Not pitching," he said. Will it go away? "It hasn't yet?" Can he throw hard with the pain? "Halfway hard," he said.

The question until Guidry's foot feels better is, "Losin' Any Lightnin'?"

Just as infuriating for the Yanks was the defensive comedy of newly acquired first baseman Dave Revering for whom the Yankees gave Oakland Tom Underwood, a perfectly serviceable starting pitcher off a rotation that has no healthy arms to spare. Revering was a klutz all night, making two errors. Once, he overran a moderately tough foul pop by so much that even after backtracking he couldn't get near the ball with a dive.

Worst of all was a Revering mental blunder in the fifth that helped explode the game. With two out, Ayala singled home a run for a 5-1 O's lead -- his third hit off Guidry. Ayala absent-mindedly ran to second base, which was occupied by Eddie Murray. In the ensuing rundown, Revering should simply have nailed Ayala for the last out. However, Revering thought there was only one out, and, consequently, gambled on getting the lead runner, Murray, going to third. All hands were safe.

Guidry left. Doug Bird entered. DeCinces, who has now had a pair of two-homer games in the last three days, crunched Bird's first pitch into the pen to turn a 5-1 contest that was still a game into an 8-1 laugher.

After the game, the No. 1 star, DeCinces, was interviewed for a half-hour. Was he talking about his 22 RBI, or the way he is finally swinging as he did in the second half of 1978, when he looked like a genuine star, not just a solid pro?

"Yes, I'm going to be on 'Good Morning, America' tomorrow," said DeCinces.

To talk about your homers?

"No," said the American League player representative. "To talk about the strike."

Oh, thanks. For one night in Memorial Stadium it was almost possible to forget what we may soon be missing.