It was late in the third quarter when, walking off a Coliseum field littered with another dropped pass, Josh Rosen made a gesture that spoke for a rivalry.
The UCLA quarterback gripped his face mask tightly, then began banging the top of his helmet, again and again and again.
He won the battle, but lost the score. He won the duel, but finished on his back.
"It's just frustrating," Rosen said. "Really frustrating."
In the first and probably only meeting between crosstown rival quarterbacks with big NFL futures, Rosen was better, but Sam Darnold was the winner, the Trojans escaping with a 28-23 victory on a night of two revelations.
First, USC was supposed to be at least two touchdowns better than the undisciplined Bruins, but something is missing with these Trojans, who played incredibly average and even uninspired for a team that is 10-2.
Second, Darnold entered the game with a season's worth of better hype, but it is Rosen who clearly is deserving the late-season headlines.
"We have the utmost respect for Josh Rosen, and I think he came out and showed exactly what he was about," linebacker Cameron Smith said. "He threw the ball over and made some big plays. ... I give credit to him, but I'm just happy we're sitting here with a win."
All the NFL scouts sitting in the second row of the Coliseum press box saw the same thing, and here's guessing they came to the same conclusion. If the 2018 NFL draft were tomorrow, Rosen would be taken ahead of Darnold, who some of the scouts surely now believe should spend one more year in school.
"I really thought we won this game," said Rosen, whose Bruins outgained the Trojans by nearly 100 yards and had five times as many third-down conversions. "I mean, we executed how we wanted."
UCLA indeed spent much of the night looking like a better team, and their quarterback won every statistic but the one that counted.
Rosen suffered through porous protection and slippery-fingered receivers to go 32 of 52 for 421 yards with three touchdowns. He also had one interception and one lost fumble.
Darnold benefited from much better protection, a much better running game, and went 17 of 28 for 264 yards with no passing touchdowns and one rushing touchdown. He also threw an interception and lost track of time to cost his team a chance at a field goal at the end of the first half.
Rosen not only won the stats test, but also the eye test. Rosen was wow, Darnold was workmanlike. Rosen showed off his arm, Darnold displayed his steadiness.
Rosen also nearly brought his team to a stunning victory despite the Bruins losing a touchdown on a penalty, defensive missed assignments, a missed field-goal try and getting fooled on a trick USC punt return that wound up being one of the most embarrassing scores in the 87 years of this series. The ball was punted to USC's Michael Pittman Jr., but nearly the entire UCLA punt team ran toward a fair-catch-gesturing Ajene Harris on the other side of the field, and Pittman ran 72 yards untouched for the game's first touchdown.
"There were just mental errors that we kind of messed up here and there," Rosen said.
Rosen began quickly, midway through the first quarter, throwing a 41-yard pass to Jordan Lasley that traveled almost 50 yards in the air, threading a pass to Austin Roberts for 15 yards, then hitting Lasley in the corner of the end zone with perfect 11-yard pass for a tying touchdown that made Rosen wildly gesture toward the sidelines in glee.
Rosen also kept fighting until the end, finding Lasley on a perfect 27-yard strike in the corner of the end zone with 2 minutes 43 seconds left to eventually close the gap to five points before UCLA's onside kick failed.
When it was finished, Rosen didn't walk toward the tunnel, but headed directly toward midfield, directly toward Darnold, where they embraced each other first.
Said Rosen: "We're friends … it's all in good sportsmanship."
Said Darnold: "It's awesome to be able to battle against a great player like Josh. Whenever we get the opportunity to play against a great team and great quarterback like Josh, you just want to compete to the highest level, and that's what we did tonight."
They both did, the two quarterbacks jabbing at the other guy's team, possession after possession, round after round.
Both men had their highlight moments. In the fourth quarter, Rosen lofted a 43-yard pass that bounced off Trojan Jack Jones' hands, then Trojan Iman Marshall's helmet, then finally into Lasley's hands.
But after UCLA could only convert a field goal to pull to within four, Darnold drove USC back down the field with a perfect 29-yard strike to Stephen Carr in full stride to set up a clinching Ronald Jones II two-yard touchdown run.
But both men also had their troubles. Darnold badly overthrew his receivers on a Jaleel Wadood interception and then, on their ensuing drive, the final of the half, deep in UCLA territory, Darnold ran the ball up the middle as the clock expired, the Trojans ending the half on the Bruins five with no chance to score.
Yet, Rosen also made mistakes, with one drive in the second quarter ending with a lost fumble on a strip-sack by Malik Dorton, and a push in the third quarter ending with an end-zone interception by Marvell Tell III.
Back and forth they went, Darnold running his offense, Rosen working his arm, Rosen ultimately getting the last touchdown pass, but USC getting the win.
On a night when Rosen was more than enough, the Bruins just didn't have enough, his personal victory ruined by UCLA's third consecutive crosstown loss.
"Not great," Rosen said. "At all."