Clausen threw three incomplete passes into the end zone in the closing seconds as No. 6 USC held on for a 34-27 victory and its eighth straight win against No. 25 Notre Dame on Saturday.
Notre Dame's streak of last-minute victories ended at three, but the Fighting Irish (4-2) at least showed they could compete with their longtime rivals this season.
USC had dominated Notre Dame and Weis the past three seasons and led 34-14 in the fourth quarter Saturday. The Fighting Irish seemed on their way to the type of lopsided loss that would have their supporters grumbling about Weis again.
Instead, Clausen and the Irish rallied back, but couldn't score into the same end zone where the Trojans (5-1) famously scored four years ago on the Bush Push, which gave Reggie Bush, Matt Leinart and USC a 34-31 victory in Weis' first season.
On Clausen's first pass into the end zone, Kyle Rudolph made juggling catch but was out of bounds. The second was knocked down by Josh Pinkard and the Trojans started celebrating thinking the game was over.
Clausen and USC quarterback Matt Barkley, pals from southern California, even exchanged what they thought was a post-game handshake.
But the officials ruled there was 1 second left. Clausen fired to Duval Kamara, who slipped and couldn't get a hand on it.
Barkley was 19 for 29 for 380 yards and two touchdowns to Damian Williams.
The Trojans appeared to be on the verge of blowing the game open when Joe McKnight dove in for a TD early in the fourth quarter.
But the Irish closed to 34-27 midway through the fourth quarter on a 2-yard TD run by Clausen and a 15-yard TD pass from Clausen to Golden Tate after an interception by Irish cornerback Gary Gray.
Clausen was 24-of-43 passes for 260 yards and two touchdown passes while facing a strong USC pass rush. He threw the ball away five times and was sacked five times. And in the end, he gave Notre Dame a chance, which is far more than the Irish have had in recent years against Pete Carroll's mighty Trojans. In the previous three meetings, USC outscored Notre Dame 120-27.
Tate had eight catches for 117 yards. The Irish also got a 25-yard completion on a faked field goal attempt by holder Eric Maust that set up another touchdown.
The Irish were aided in their final drive by a couple of penalties by USC. Robby Parris caught a 13-yard pass on fourth down to the USC 16, but All-American Taylor Mays was called for a personal foul on the hit to Parris. That got the ball to the 8. Then Malik Jackson was called two plays later for roughing the passer, placing the ball on the 4.
But the Irish couldn't get the game to overtime and USC celebrated its 10th straight win against a ranked opponent. The Irish lost their seventh straight to a top-10 team, matching the longest streak in school history set from 1984-1986.
Barkley wasn't at his sharpest early, frequently keeping his receivers waiting for passes, in the first half. But after throwing an incomplete pass on his first attempt of the second half, he completed his next eight passes for 195 yards to help the Trojans take a 27-14 lead. That included a 41-yard TD pass to Damian Williams and a 60-yard pass to Anthony McCoy that set up a 3-yard Allen Bradford run.
In USC's 38-3 victory in Los Angeles last November, the Irish didn't get a first down until the final play of the third quarter and finished with 41 yards passing and 50 yards rushing. On Saturday, the Irish got a first down on their second play when receiver John Goodman ran for 13 yards out of the wildcat and had 72 yards passing and 49 yards rushing in the first half.
The Irish had five first downs in the first quarter, one more than they had the entire game last year.