SOUTH BEND, IND., NOV. 17 -- With no Rocket to turn to in the second half, No. 1 Notre Dame thudded to earth this evening in the grand tradition of all of 1990's top-ranked teams.

Penn State, down by two touchdowns at halftime, upset the Irish, 24-21, when freshman Craig Fayak made a 34-yard field goal with four seconds remaining after Rick Mirer was intercepted in Notre Dame territory with a minute to go.

The Nittany Lions scored 10 points in the final 7:15 as junior Tony Sacca played the game of his life, throwing for 277 yards and three touchdowns on a 20-for-34 day.

The Irish lost all-purpose threat Raghib "Rocket" Ismail when the bruised thigh he has had since the second game of the season tightened up at halftime. He played just the first half, handling the ball only 10 times, and gained 109 all-purpose yards. In the second half, Notre Dame gained only 75 total yards and never moved into Penn State territory.

"I don't believe it," said Notre Dame tailback Ricky Watters, who gained 114 yards and scored the game's first touchdown. "We had everything going on all cylinders and in the second half, I don't know what happened."

The shocking loss before an estimated 59,000 at Notre Dame Stadium dropped the Irish to 8-2, made second-ranked Colorado the certain No. 1 team in next week's polls and improved streaking Penn State to 8-2.

The Irish, their national title hopes apparently dashed, still will go to the Orange Bowl to play the Buffaloes, three Orange Bowl officials said here tonight. They said there is "no chance" Miami, bound to move to No. 2, will take Notre Dame's place and get an opportunity to play at home against Colorado.

"We know what we're doing," said bowl official Nick Crane. "We're taking Notre Dame. It's still a great game."

That is, if Ismail is healthy. The Irish are a wonderful offensive team with him, stunningly mediocre without him.

"Rocket missed most of practice this week and {the leg} tightened up on him at halftime," said chagrined Coach Lou Holtz.

"He's a great football player. When you don't get great field position, and we didn't in the second half, they can cover us man-to-man, and you know who we'd go to if it was man-to-man. There is no doubt a lot of our offense is built around Rocket."

Without him, the Irish could not recover from two Mirer mistakes that set up 10 Penn State points.

The first interception allowed Penn State to close the gap to 21-14 with 32 seconds left in the third quarter. Mirer, lined up at his 43, was intercepted by linebacker Mark D'Onofrio, who returned the ball 38 yards to the Notre Dame 11.

Three plays later, backup tight end Rick Sayles slipped behind Irish freshman cornerback Jeff Burris in the end zone and Sacca found him there. But this was not an easy reception. Sayles bobbled the ball four times before gathering it in as his feet came together in the corner of the end zone for an 11-yard catch.

Two possessions later, Penn State tied the game with 7:15 left when Sacca threw a 14-yard pass to tight end Al Golden. Sacca rolled right, then spotted Golden open across the field on the left sideline for the touchdown.

Notre Dame, which managed just two first downs in its miserable fourth quarter, then punted, and Penn State moved to the Notre Dame 37 before punting back. Beginning from his 7, Mirer led the Irish to the 19, where, on third and eight, he badly overthrew wide receiver Tony Smith.

Waiting for the ball was safety Darren Perry, whose position appropriately is listed as "Hero" in the lineup. (Many schools give free safeties names, like "Monster" back. Penn State chooses "Hero.") Perry returned the ball to the 19, where the Nittany Lions ran the clock and set themselves up for the winning field goal, Fayak's first of the game after missing a 39-yarder in the third quarter.

When Notre Dame roared to touchdowns on its first two possessions -- Watters's 22-yard run with 10:39 to play in the first quarter and backup tailback Tony Brooks's 12-yard run with 6:34 left -- the game looked like an Irish rout.

But the Nittany Lions sprang to life with a nifty touchdown of their own two minutes later. Coach Joe Paterno dug deep into his bag of tricks and came up with a fake handoff-fake reverse, which worked perfectly when Sacca hit wide receiver Terry Smith for a 32-yard touchdown with 4:29 left.

This required a certain amount of acrobatics on Smith's part. He leaped to catch the ball in front of cornerback Todd Lyght at the 5, then took a hit from Lyght and spun backwards toward the goal line. By just barely keeping his balance, Smith stumbled into the end zone on his back, and Penn State had its touchdown with 4:29 remaining in the quarter.

Notre Dame scored its final touchdown on Mirer's one-yard sneak to end a 16-play, 92-yard drive with 5:00 in the first half.

At halftime, Paterno told his players to stop thinking Notre Dame was so good.

"I think we had too much respect for their receivers and we were giving them too much room," Paterno said. "I told them we had to go after them."

Statistics spoke volumes for the Penn State change. In the first half, sophomore Mirer, who is good, but not great, was seven for 12 for 140 yards. In the second half, he was one for nine for 21 yards. Two other passes went to Penn State.

"We were hoping to get them to throw the ball," said Paterno.

"Rick probably wasn't used to not having success in moving the football," said Holtz. "We never got into a rhythm in the second half."