As dusk fell on Pitt Stadium this afternoon, the Penn State band struck up college football's theme song for 1981: "Another One Bites the Dust."

It was a jubilant rendition, one that few of Pittsburgh's fans were around to hear. Because today, with 60,260 chilled spectators watching in amazement, Penn State crushed Pitt, 48-14, making the Panthers the sixth No. 1 team to crash this season. Pitt's loss left Clemson as the only major unbeaten, untied team in college football and an almost sure bet to become the seventh No. 1-ranked team this season when the polls come out this week.

"We just got the momentum turned against us the wrong way," said Pitt Coach Jackie Sherrill, whose 10-1 team had a 17-game winning streak broken. "We had the locomotive going against us the wrong way and nothing to stop it with."

What made the lopsided outcome so astonishing was the way game began. Pitt came out as if it intended to chase Penn State back into the Nittany Mountains, rolling to touchdowns on its first two possessions. First the Panthers drove 53 yards, scoring on Dan Marino's 28-yard pass to Dwight Collins, then went 64 yards to score on Marino's nine-yard pass to Collins.

"The first quarter Marino was just unbelievable," Penn State Coach Joe Paterno said. "We had to make some adjustments against him." v.hen the quarter ended, Pitt was leading, 14-0, had driven to the Lions' 31 and had held Penn State to minus-one yard in offense. Marino had completed nine of 10 passes for 121 yards.

"It looked like we were going to blow them out," said Collins. "I think maybe we relaxed a little bit, let down and let them get back in it. You can't let a team with their talent get started on you."

But from the first play of the second quarter, when Marino tried to find Collins with a pass lobbed into the corner of the end zone and was intercepted by Roger Jackson, until the end, the Panthers appeared helpless. That was the first of the Pitt quarterback's four interceptions; for the game, he completed but 13 of 35 passes.

"That's one of the problems with their schedule," said Penn State linebacker Chet Parlavecchio, who this week had called the Panthers' schedule "like going through a Bermuda sun shower. They've been crushing people early all year. They haven't had to come from behind. It's like not having something covered. They haven't had a chance to practice it. We have."

The Lions rallied with a vengeance today. Spurred by Jackson's interception, the first indication that Pitt was mortal, they went 80 yards for their first touchdown, closing the margin to 14-7 after fullback Mike Meade went over from the two with 11:55 left in the half.

That score was set up by Todd Blackledge's 28-yard pass to tight end Mike McCloskey, a play on which the sophomore quarterback read a blitz correctly. For Blackledge, as for Paterno, this was a day of vindication after Lions' humiliation by Alabama two weeks ago.

oday, Blackledge was 12 of 23 for 262 yards and two touchdown, both the scoring passes going to Kenny Jackson. "There was a lot written this week about Marino and me, most of it negative toward me," Blackledge said. "I tried to use it as an inspiration and motivation."

From Paterno, who ran into the field before the game and began jumping up and down and shaking his fists in very un-Paterno-like fashion, down through the water boys, this was an inspired and motivated team.

Most inspired perhaps was Parlavecchio, who had rapped Pitt and its schedule all week. "We came down here to beat Pitt and beat them bad," he said. "I just decided this wasn't going to be in the subtle bowl."

It was an unsubtle late hit by Parlavecchio on Pitt's drive after the first Lion touchdown that seemed to turn this game. Parlavecchio hit Collins out of bounds so hard that Sherrill came running down the sideline to yell at him.

"Maybe I'm crazy, but that play served its purpose," Parlavecchi said. "After that, we were sparked. And all their linemen were talking about 'get Chet, get Chet' instead of worrying about blocking."

A simplification maybe. But five plays after the late hit, Marino tried to pass to Julius Dawkins on the play that had produced the first touchdown. This time, Roger Jackson smacked the ball loose and Mark Robinson intercepted it. Again, Pitt was stopped.

"By then they knew they couldn't break us," Robinson said, who went to John F. Kennedy High Scool in Silver Spring, Md.

Two series later, after an exchange of turnovers, the Lions went 80 yards, Blackledge's 52-yard pass to Kenny Jackson setting up an eight-yard quarterback draw that tied the score at 14 with 2:42 left in the half.

Pitt had a chance to go ahead before the break when punter Dave Hepler avoided a rush to get off a kick, spraining his knee in the process, and Kenny Jackson fumbled the ball at the 40. But fullback Wayne DiBartola fumbled and the Lions' Greg Gattusso recovered at the 16.

It was even at the half and Pitt had turned the ball over four times in the second quarter. "We were lucky to only be tied," Sherrill said. "Of course, without the turnovers we might have had 28 points. That's what killed us."

"I knew right then we had them," Parlavecchio said.

He was right. Backup fullback Bill Beach fumbled on the Panthers' first series of the second half and, three plays later, Blackledge passed to a wide-open Jackson on the 10. Jackson did a 360-degree turn away from two defenders and danced into the end zone for a 42-yard score and a 21-14 lead.

Pitt couldn't move, punted and Blackledge and Jackson teamed up again, this time for 45 yards. In less than six minutes, the Lions had a 28-14 lead. From there it just built, climaxing in Marino's final errant pass, grabbed by Robinson and returned 91 yards.

"They were better than us, they deserved to win," Marino said. "We didn't adjust, they did. That's how upsets happen."

"This wasn't an upset," said Blackledge. "Joe didn't think of it that way and neither did anyone else. We came in here expecting to win the game."