Somewhere back there, Tony Dorsett had the football. The littlest Cowboy wanted to run loose. That much, L.C. Greeenwood knew. But the big Steeler defensive end couldn't get to Dorsett because a Cowboy lineman was in the way. Inconsiderate, really. So Greenwood had no choice.

"The only thing I could do," Greenwood said, " is throw the lineman into Dorsett."

L.C. Greenwood could throw Montana into Canada. You've seen those TV commercials for Steelers' tires; at 6-foot-6 1/2 and 250 pounds, Greenwood begins each day by dunking four radials in his morning coffee. Soon enough, that Cowboy lineman was falling out of the sky, a 260-pound bean bag dropped onto Tony Dorsett's head.

Four-yard loss.

Because the Dallas Cowboys have been wonderfully successful for so long, because they come with this image of geniuses at work with computers dreaming up unstoppable plays for flawless athletes -- because, let's be honest, they have cheerleaders wearing handkerchiefs -- the Cowboys have become America's sweethearts.

Meanwhile, the Steelers have won more Super Bowls than the Cowboys, three to two, and the Steelers have beaten the Cowboys now four straight times, counting today's 14-3 victory and last year's 35-31 win in the Super Bowl.

"Some circumstantial evidence is very strong," said Thoreau, "such as trout in the milk." As evidence of football superiority, a four-game wining streak is at least a big bass in a sctoch glass. The Steelers have beaten the Cowboys at home, on the road, at a neutral site, have beaten them with offense (Terry Bradshaw's four touchdown passes in the Super Bowl) and have beaten them with L.C. Greenwood and his fierce defensive chums rendering Roger Staubach first uncomfortable and then unconscious (today).

Greenwood knocked out Staubach with a head-on tackle.

"Head-on, head-on," Greenwood said tapping his forehead to demonstrate that he met Staubach to demonstrate that he met Staubach directly. Staubach had completed 11 of 25 passes for only 113 yards before the knockout early in the fourth quarter. Staubach didn't play again. He rubbed his head a lot, though.

The Steelers have beaten the Cowboys so often you would expect them to be shouting it to America.

Meet Dwight White, defensive tackle.

"Burnt-out computer in Dallas," White shouted in the Steelers' dressing room.

White is a bright guy with a quick smile. No meanness in White here. The job was done, done well, and now White was having his gentle fun.

"You got any pull with IBM?" White asked a bystander, smiling slyly.

"The Cowboys will have to junk that computer of theirs."

White said he had bumped into Harvey. Martin, the Cowboy defensive end, coming off the field.

"Harvey said we were lucky," White said. "I told him, 'Jeez, Harvey, don't go on with that rap.'

"We'll see them again in Pasadena," the site of the Super Bowl in mid-January.

"Nobody's going to beat the Cowboys in the NFC," White said.

Both numbers and eyes tell us the American Football Conference is stronger than its brother the National. So someone asked White if he thought the Cowboys were the second-best team in the National Football League.

"Oh yeah. Dallas is a fine football team. Anyhow who's going to beat them in the NFC? The Eagles? Vikings? The Browns? Giants? Redskins?"

White pronounced each team's name with utter disbelief that they could be mentioned in the same breath with Pittsburgh and Dallas.

"You could go ask a nun in a convent and she'd have to admit that competition in the NFC is not up to what it is in the AFC."

And now said White, a nine-year veteran, the Steelers have separated themselves from everyone, even the Cowboys.

"We really beat them this time. The Super Bowl was not as intense as this game. They wanted to prove something but they got a sound whipping."

Did White have a lot of fun today?

"Oh yes," he said. 'Everybody likes to beat America's favorite team."

Not that he was belittling the Cowboys: "They have great players. We just have more great players."

And what would White think now if he were, by some unfortunate turn of fate, a Cowboy?

"I'd really start to respect the Pittsburgh Steelers. Cut off the lip service. If any group of people ought to be convinced by now that the Steelers are a great football team, and if the Cowboys are intelligent people, as I know they are, they will admit it."

Pittsburgh sent cornerbacks and linebackers on blitz-runs at Staubach all day long, much more than normal in an attempt, largely successful, to force him into quick passes. In addition, the Steeler defense backs were superb, seldom giving the Cowboys space, always closing it in a hurry. And Greenwood, White and their front-four playmates were both resourceful and mighty.

"They knew when they caught a pass," said Mel Blount, a Steeler cornerback, "that they were going to get hit. And any time you'd think about that, you are going to have trouble catching it. There were indications of that today."

Even on the Cowboys' single scoring drive, they dropped four passes and juggled another. The star receiver Tony Hill, did not catch a pass. The Cowboys' longest pass gained only 23 yards. Take away runs of 12 and 21 yards which led to nothing, Tony Dorsett gained only 40 yards on 17 other tries, nine times getting one yard or less.

"Was it entertaining?" said Joe Greene, the Steelers' patriarchal defensive tackle, who thought it was a barrel of fun.

"It was a very satisfying victory because the Cowboys are a helluva football team. They come to play, and they played well. We just played better. There wasn't anything flukish about it. They didn't have their best day, but they didn't have an off-day either. They were good. We were just better."