USC’s offense had it’s signature win against Ohio State. The Trojans on defense now have theirs.

USC’s 34-27 victory over Notre Dame culminating in a last second goaline stand caused Trojan fans just as much emotional strain as the win over the Buckeyes but carried much more weight.

Everson Griffen was called for an excessive celebration penalty after flexing his muscles following a sack of Jimmy Clausen. - Dieuwertje Kast | Daily Trojan

Why? Because it happened on this field, in this rivalry.

The Fighting Irish had all the momentum in the final minutes and were getting all the favorable calls as they drove down to the USC 4-yardline trailing by one touchdown. In just under 10 seconds, they would have three chances to tie the game.

Each time, USC’s defense answered the call.

“This seems to be the theme of our season — close situations,” linebacker Chris Galippo said.

It didn’t even bother the Trojans that they had to win the game twice. After Clausen’s first attempt fell incomplete, he lined up with four seconds on clock and threw a pass to receiver Golden Tate that hit the ground as the clocked clicked down to double-zeroes.

The Trojans started rushing the field to celebrate their eighth straight victory over Notre Dame before the officials announced that they would review the previous play to see exactly where the time ended.

Talk about throwing a bone to Notre Dame. How often does the clock stop precisely when a pass falls incomplete? And it should go both ways — I doubt they checked if the clock started exactly when Clausen snapped the ball.

But even though USC fans were probably punching their TVs and cursing the referee crew, the Trojans on the field didn’t seem to mind.

They just went out and did it all over again, providing blanket coverage on another Clausen pass and sealing up the win in a signature stand.

“It was a great moment,” coach Pete Carroll said. “Whether we had to go back again or not, that just doubled the fun of trying to get it done.”

For those Trojans on the sidelines, it may have been a bit more stressful.

“I don’t know how many chances you can get,” receiver Damian Williams said, adding, “They got off three plays in nine seconds, I’ve never heard of that. But our defense did a great job.”

Ironically, the defense did not play well during a long stretch in the fourth quarter. Quarterback Matt Barkley and the Trojan offense seemed to put the game out of reach, building a 20 point lead early in the fourth quarter. But Notre Dame quarterback Jimmy Clausen capitalized on the somewhat complacent Trojans, scoring two touchdowns fairly easily and getting in position to win the game at the end.

But for all all the mistakes and blown coverages, the Trojans came through mentally when it counted.

They were able to overcome four personal foul penalties in the second half, three of which were blatantly bad calls, especially the one on defensive Everson Griffen for excessive celebration when Griffen flexed his muscles after sacking Clausen. (Count how many times that same celebration is made the rest of the season and not called a penalty. Believe me, you’ll need more than just your fingers and toes.)

USC safety Josh Pinkard admitted the bad calls frustrated him — “Goodness, let us play man,” he said he was thinking — but it never affected him beyond that. After all, Pinkard was the one who broke up Clausen’s pass to Tate on the second to last play of the game.

The Trojan defense as a unit wasn’t fazed either, able to keep the most important play — the current one — at the forefront of their minds.

“They maintained a level of poise to make the right decision at that time,” defensive coordinator Rocky Seto said.

It is not only the gap in talent level that has allowed USC to dominate Notre Dame over this decade. It’s not the X’s and O’s either.

What it comes down to is the mentality, the winning attitude that Carroll has so completely cultivated in his players’ minds that they never think games are going to end in anything but W’s.

“Everyone in that huddle, everybody on that sidelines, that’s all we’ve known,” Carroll said. “We prepared our mindset [so] that’s all we know.”

As clear as this is on USC’s sidelines is how much it is apparently lacking on Notre Dame’s. You could hear it in Notre Dame coach Charlie Weis’s words leading up to this week. You could see it in the desperation the Irish played with Saturday and with which their fans cheered. They were begging for this game, a longing dating back to 2001.

But wanting it bad enough doesn’t win games. When it comes down to it, believing in yourself and your team separates the champions from the wannabes. The USC defense came through because it never doubted that it would.

“You want to have that mentality if it goes to that last play,” Carroll said. “We’ve been talking that way and preparing the way we prepare to build legitimacy to that mindset. Again, we had a chance to back it.”

The defense certainly took advantage of that chance to back it up, giving Trojan fans another game to be remembered in the USC-Notre Dame rivalry and another reminder why USC’s remarkable run under Carroll doesn’t seem to be stopping any time soon.