The New York Yankees brought up Joe Lefebvre this week to play left field. But they forgot to buy him a ladder.

The rookie -- symbolic of the panic mood on the bridge of the S.S. Steninbrenner -- spent the night climbing the Memorial Stadium fence to watch Baltimore Oriole home runs streak over his head: three of them.

A raw sense of Yankee fear and disorientation plus an undisguised Oriole thirst for the jugular were obvious in this sweatbox park tonight as the Birds ground down the Yanks, 6-1, for their fourth victory over New York in seven days.

This pennant race is beginning to resemble the Boston Massacre of '78 -- but this time the Yankees are the prey, not the hunters.

Exactly a month ago -- July 14 -- the Orioles trailed by 11 games. Now, after going 22-7 while New York is 14-16, they are 2 1/2 games back and have the New Yorkers scheduled for four more garden parties here in the hostile, howling brickyard on 33rd Street.

The Birds presented Manager Earl Weaver with a golden 50th birthday present in the form of a dazzling Steve Stone two-hitter, plus late-inning home runs from Gary Roenicke, Rich Dauer and Ken Singleton.

This game, unlike the three close affairs last weekend in New York, seemed like a celebration of Orioles' vengeance for the first five months of embarrassment that the defending American League champions have been birdled under this year.

Wine-connoisseur Stone, a presumptive little 1980 with a 19-4 record now, was in vintage form with a 135-pitch, conrner-nipping effort, the second two-hitter of his career and the lowest-hit game against slumping New York this year.

After Stone set down the Yanks in order in the first, and the Orioles greeted starter Tom Underwood with two runs in the bottom of the inning, this game was in the Bird nest.

However, it was the late-game crescendo of homers -- all three smashing within a yard of each other on the bleacher wall beyond the fence, like well-grouped target rifle shots -- that gave this game an extra dimension.

The first, by Roenicke with a man on in the sixth, knocked out Underwood and effectively ended the game. That blow was enough for a 4-1 lead, and enough to get the crowd of 49,952 (fifth largest in Oriole history) on its feet waving its "I Hate N.Y." bed-sheets. It was even enough to get Edward Bennett Williams, team owner, on his feet screaming as he illustrated the parabola of the homer with his hand as though he were in a courtroom describing the trajectory of a fatal bullet.

If Roenicke's blast was substance, then the back-to-back ropes by Dauer and Singleton -- on consecutive Ron Davis pitches in the seventh -- were the sort of symbolic blows on which a pennant race and the self-image of a team, can subtly change.

When Lefebvre climbed the fence in vain for Dauer's smash -- which hit the same exact spot as Roenicke's, -- the Orioles had to laugh.

"The hostage had been released," crowed the O's Doug DeCinces, referring to the 296 days since Dauer's last homer in World Series. "The pitchers have had him locked inside the park longer than the hostages in Iran (11 days longer)."

Dauer, after his first four-bagger in 392 at-bats in '80, was soon shaking Singleton's hand after a liner so nearly identical to the previous two -- just to the right of the 360-foot stirps and left of a sign saying "Tippy's Tweeners" -- that it seemed the O's were taking target practice.

"When Singleton's ball was going out, I just watched Bucky Dent shrug at shortstop," said DeCinces. "It was like he was saying, 'It's all slipping away.'

"You could see it on their whole team tonight. The only one who's still carrying them is Reggie (Jackson). They have great players and we respect them," added DeCinces."But the game last Sunday had to break their backs.

"Now, they're in our park, not theirs," said DeCinces, "and right at this moment, we're so hot and playing so well, that we have the feeling there really isn't much they can do about it."

Jackson tried tonight to be a one-man show. After the Birds scored two runs in the first on a four-pitch leadoff walk to Bumbry, a full-count hit-and-run RBI double to the right center field alley by Dauer and an RBI single to center by Bennie Ayala, Jackson gave his one-swing answer.

The first man up in the Yank second, Jackson laced a high Stone curve into the New York bullpen to cut the deficit to 2-1, his 32nd homer of the year and 401st of his career.

In the fifth, Jackson saved a run with a two-out; belly-flopping catch of a soft liner by Singleton that was the best sort of raw-speed play of which Jackson is capable. He also drew a walk. But after a pair of two-out walks in the Yankee third (the only time New York had a base runner past first), Jackson cracked a liner to left that Al Bumbry raced down in the gap.

When Jackson wasn't at bat, the Yankee lineup -- with rookie Lefebvre and now-paunchy, much-traveled Aurelio Rodriguez at third -- had a make-shift look.

"I just have to keep producing," said Jackson, who has 86 RBI. "If a ship is filled with holes in the hull, it still won't sink if the ship is strong enough. I just hope we don't have too many holes."

The Orioles are so confident of the state of their ship that they seem to have taken a near vow of silence, as though convinced that as long as they don't arouse the slumbering Yankees, they will prevail. The more easily they win -- five straight now over New York in '80 since losing their first four -- the more bouquets they toss to the leaders.

The Birds are now 38-16 (.704) since June 15 (a full third-of-the-season stretch), have won nine in a row at home and have won their last 13 consecutive decisions over left-handers. This is a team so hot that it's only worry is melting.

But the hottest Oriole is Stone, 20-2 in Memorial Stadium as an Oriole (12-1 this season) and 24-4 overall since July last year.

"If I can't enjoy this year to the fullest. I ought to get out of the game as an ingrate," said Stone. "It's been a wonderful experience and I've relished evry facet of it. You learn to savour the good when you're a .500 pitcher for so long.

"Somehow . . . maybe it's being part of this team . . . I feel no pressure at all," said Stone, who ended the game with a flourish, fanning Rick Cerone. "I just think of this race as the nice part -- the reward. It sure beats the hell out of last year when 50,000 people were booing me when I was 6-7, and you had to give 10 of my baseball cards to get one of anyone else.

"Tonight was typical," said Stone. "I took an inventory of my stuff and I made adjustments. My control was excellent, as good as any time this year. My curve hasn't had as much bite after all the innings this year, so I used my fast ball more."

Last Saturday, when Stone also outdueled Underwood, it was hiss slider -- unveiled in midgame -- that led him to a seven-hitter. Tonight, it was the fastball and control.

"In my other two-hitter, I lost, 1-0," said Stone "so I decided I wouldn't pitch any more of them."

In many ways, Stone is the quintessential Oriole -- delighted to be part of this team, limited in talent but virtually presure-proof and a trifle self-deprecating.

Is Stone surprised that crowds can go from boos to cheers, that people now ask him about every facet of himself?

"It's tough to overlook 19-4," Stone grinned. "But I doubt if the Yankees have read my (published) poetry yet."

Tonight, they watched Stone's poetry.

It is unlikely that they will be able to over look either Stone or his team any longer.