dieffenbach

Behind a standout performance from quarterback Ty Dieffenbach in his first UCLA start, the No. 12 Bruins defeated Wisconsin 17-7 at the Rose Bowl on Saturday.

Dieffenbach orchestrated a six-play, 89-yard drive in the fourth quarter to help seal the win for the Bruins, who clinched bowl eligibility by improving to 6-0 under coach Bob Chesney. UCLA is the only undefeated team in the Big Ten.

Although UCLA (6-0, 4-0) entered with one of the most potent ground attacks in the nation, the Badgers’ (4-2, 2-1) stalwart defense — a unit that ranked No. 15 in total defense and ninth in passing yards allowed heading into the game — held UCLA to just 3.2 yards per carry. Heisman Trophy contender Wayne Knight was limited to just 29 all-purpose yards, though he scored his 12th touchdown of the season.

With UCLA struggling to get a push at the point of attack and the Wisconsin defense sealing the edge, the Bruins put their trust in Dieffenbach, who started in his first Football Bowl Subdivision game following Nico Iamaleava sustaining a knee injury against Oregon last week that could keep the senior out for the remainder of the season.

The understudy shined in the spotlight.

Even though expectations were tempered for Dieffenbach, he largely did not miss a beat, completing 22 of 33 passes for 264 yards — better than any single-game passing yards total Iamaleava has produced at UCLA.

Dieffenbach set up UCLA’s first touchdown in the second quarter when he completed a 21-yard pass to Jalen Saint Paul one play before Knight scored on a one-yard carry.

UCLA running back Wayne Knight breaks a tackle from Wisconsin safety Marvin Burks Jr. during the second quarter Saturday.

(Ronaldo Bolanos / Los Angeles Times)

UCLA’s second score — a touchdown that put the Bruins up 10 points in the fourth quarter — capped Dieffenbach’s most impressive drive. Starting at the UCLA 11, Dieffenbach connected on passes of 28 and 33 yards on a drive that culminated with Anthony Woods scoring on a three-yard run.

Dieffenbach looked poised in the pocket as he made passes under pressure. He excelled on third down, with UCLA converting on 13 of 20 tries. He threw one interception, which came on a Hail Mary as expired in the second quarter, and took just one sack.

Giving Dieffenbach some breathing room, UCLA’s defense dominated again, holding Wisconsin to 214 total yards. Even without UCLA starting outside cornerback Rodrick Pleasant, the Bruins’ secondary blanketed the Badgers in coverage, giving up just 66 passing yards, with Wisconsin’s top receiver Jaylon Domingeaux finishing with 26 yards.

Wisconsin running back Darrion Dupree is tackled by UCLA defensive lineman Sahir West during the second quarter.

(Ronaldo Bolanos / Los Angeles Times)

And while the “Bruin Bullies” held up at the line of scrimmage against the Badgers’ tailbacks, Wisconsin quarterback Colton Joseph ran for 71 yards and one touchdown, using various formations and fakes to confuse the Bruins’ stacked box.

While UCLA failed to produce a takeaway for the first time this season — despite forcing two fumbles, both of which were recovered by Wisconsin — the Bruins made several key stops to help UCLA stay in control.

A 10-yard sack from fifth-year linebacker Jalen Woods on third down late in the second quarter led to an unsuccessful 46-yard field-goal attempt by Gavin Lahm, leaving Wisconsin scoreless at halftime.

UCLA wide receiver Brian Rowe Jr. celebrates after making a catch in the second quarter Saturday against Wisconsin.

(Ronaldo Bolanos / Los Angeles Times)

After Wisconsin scored its only touchdown and subsequently forced UCLA into a three-and-out late in the third quarter, the Badgers had the ball with a chance to take the lead. But the Bruins forced two incomplete passes and stuffed Joseph at the line to force a punt.

In the fourth quarter, UCLA stopped running back Darrion Dupree short of a first down on fourth-and-two at the Bruins’ 48 to all but end the Badgers’ hopes of a comeback.

Ty Dieffenbach, a former Cal Poly and Pittsburgh signal caller, wasn’t well known among UCLA and national college football fans until last week.

Dieffenbach has been patiently waiting for his moment since he made the switch from wide receiver to quarterback as a sophomore at Agoura High.

And like subbing in to play quarterback at Autzen Stadium and leading UCLA to the biggest win of the season thus far, his football journey has never been a layup. But that’s what makes Dieffenbach’s first Football Bowl Subdivision start against Wisconsin Saturday at the Rose Bowl so special.

Dieffenbach was a wiry 6-foot-3 receiver preparing for his sophomore season in 2020 when coach Dustin Croick took over the Agoura football program.

Ty Dieffenbach switched from playing receiver to quarterback at Agoura High.

(Eric Sondheimer / Los Angeles Times)

Teams had to wipe down the balls after using them during the COVID-19 pandemic. Once players were cleared to return to practice after a long break, Dieffenbach routinely ran a route, caught a pass and threw the ball back to the start of the drill.

Dieffenbach was throwing deep passes with perfect spiral in front of Croick, who lacked a starting quarterback.

Dieffenbach agreed to switch to quarterback and committed to intense training that move required.

Croick and Dieffenbach worked via Zoom to study schemes, installations and the skills it took to play under center. What would have been a grueling process for most, was an escape for Dieffenbach, who was struggling through the most adverse time in his life — his mother’s bout with breast cancer.

“He’s a sophomore. His mom was just diagnosed with breast cancer. So you have a kid that’s going through that, and the quarterback stuff was his outlet, going through the hardest thing that he’s been through off the field and something super personal,” Croick said. “Football was his medicine at that time, where it wasn’t as serious as what he was going through.”

Through it all, Dieffenbach learned how to be a quarterback and a leader. After going 7-3 and breaking the school’s single season touchdown passing record Croick once held, all of the team’s star players graduated.

And Dieffenbach, who was racking up college offers, was left with a depleted roster and a grim senior season outlook. But while top-tier high school programs tried to lure him away, it was never a question.

It was always Agoura.

“He’s getting calls left and right from other schools to transfer to big time schools that are in our area. And I remember the conversation with his dad and him. I told him if you’re going to leave, you’re still my boy. I still love you, and I get it,” Croick said. “And he’s like, absolutely not. I would never leave, because I’m Agoura. I’m A-Town, and I’m here. And to be honest, from my perspective, back then he should have left. But that’s the type of kid he is.”

Despite a 1-9 record and a knee injury sustained in Week 1 that kept him out of the rest of the season, Dieffenbach’s loyalty never wavered, and the Calabasas product was rewarded with a late offer from Pittsburgh, making him one of the first Power Four football players out of Agoura in more than a decade, Croick said.

After not seeing any action as a true freshman, he was frustrated by the lack of playing time but stayed the course, working to see the field the following season. However, after offensive coordinator Frank Cignetti Jr. was fired following a 3-9 season, his outlook at Pitt went from bad to worse.

New offensive coordinator Kade Bell wanted Dieffenbach to make another position switch, this time from quarterback to tight end.

UCLA quarterback Ty Dieffenbach helped lead the Bruins to a win at Oregon on Oct. 10.

(Lydia Ely / Associated Press)

Dieffenbach’s loyalty was tested a second time.

Take a leap of faith and leave Pitt after two seasons without playing, or stay at a program and a school where he felt comfortable.

“It was very hard for him to leave Pitt because he didn’t want to. He felt good there. He had really good friends there. But you can’t control a new offensive coordinator. You can’t control them wanting to do a position change or anything like that,” Croick said. “He just believed in himself to play quarterback. He said, ‘I want a shot at playing quarterback. If I don’t ever do that, I won’t know, so I need to do it.’”

Dieffenbach transferred to Cal Poly. After winning the starting job during preseason camp, he finally had the chance to see the field at the college level.

But injuries altered his season, consistently playing at less than 100%, missing time and never really finding a groove.

Cal Poly quarterback Ty Dieffenbach throws a pass against Utah on Sept. 6, 2025, in Salt Lake City, Utah.

(Chris Gardner / Getty Images)

“He got hit in the back, and there were some issues there, bruising and pain, and that was a lot to have to fight through,” former Cal Poly head coach Paul Wulff said. “When you have an injury and you’re playing and you’re sore, it affects you. It’s not that easy, so he had to overcome that, which was hard for him. But he kept plugging away at it, and he finally got a little bit better and got a little more confident, and the pain wasn’t as much, but it lingered all season for him.”

And after a 4-8 season, Wulff left Cal Poly and Dieffenbach faced another crossroads.

It was not until new UCLA coach Chesney and offensive coordinator Dean Kennedy took over the Bruins that a new opportunity arose. He decided to join the UCLA roster with no guarantee he would earn snaps at a school with an established starter and a returning backup.

He earned the respect of his UCLA coaches and teammates, who were not surprised by how Dieffenbach responded when Nico Iamaleava was injured during a top 25 game at Oregon.

After leading the Bruins to their first win at Autzen Stadium since 2004, Dieffenbach earned the right to replace injured Iamaleava in the starting lineup.

“He’s been able to withstand some difficult times of not playing at Pitt or getting injured at Cal Poly. At the end of the day, he believes in himself,” Croick said. “Even at Pitt, I told him you’re going to get your shot. You just got to stay locked in. He never wavered. If you go to his time at Pitt, it was super important for where he is right now.”

UCLA senior starting quarterback Nico Iamaleava will miss the rest of this season with a knee injury, according to a person with knowledge of the injury not authorized to discuss it publicly.

The injury is a blow for the No. 12 Bruins, who are 5-0 during coach Bob Chesney’s first season and have a favorable path to a spot in the College Football Playoff.

Iamaleava sustained the injury at the end of the first half of UCLA’s win over Oregon.

The quarterback was running with the ball when he was spun around and was tackled. He grabbed his leg as he was hit in the head by Oregon’s Bear Alexander. Iamaleava briefly returned for one play and Chesney said during a halftime TV interview the quarterback was fine after getting hit in the quad.

Iamaleava, however, did not return with the team after halftime and eventually emerged from the locker room in the third quarter wearing street clothes.

UCLA quarterback Nico Iamaleava is examined by medical staff while coach Bob Chesney watches Saturday in Eugene, Ore.

(Lydia Ely / Associated Press)

Before his exit, Iamaleava went 10 of 17 passing for 162 yards and two interceptions. Through five games, the quarterback tallied 982 passing yards, 144 rushing yards, five total touchdowns and four interceptions.

After Saturday’s win, Chesney said that he thought Iamaleava injured his thigh, but he noted the injury may have been more extensive and it would require a full medical evaluation.

Senior quarterback Ty Dieffenbach, who had been listed third on the depth chart behind Iamaleava and his younger brother Madden, ran the UCLA offense during the second half. He completed three passes for 43 yards and one touchdown, helping the Bruins earn a 17-15 win.

“When someone goes down, and someone’s gotta step up, you’re either exposed or you’re revealed,” Chesney said. “One of the two is going to happen when your number gets called, and for Ty to step up in that moment when Nico couldn’t go and to put himself in the spot where he was revealed for knowing the run game, knowing what to get us into, the touchdown pass I thought he threw.”

Madden Iamaleava appeared in two games this season, taking over the offense against Purdue when his older brother went down with a shoulder injury and against Maryland with UCLA up multiple scores.

Chesney turned to Dieffenbach, who started last season at Cal Poly, during one of the biggest moments of the season. Dieffenbach said after the win he didn’t know he would be asked to lead the offense if Nico Iamaleava was knocked out.

UCLA quarterback Ty Dieffenbach prepares to receive the ball during a win over Oregon Saturday in Eugene, Ore.

(Lydia Ely / Associated Press)

The decision to play Dieffenbach instead of Madden was based on the game script and the threat of Dieffenbach in the ground game, Chesney said.

“We are really on a week-to-week basis here, and this week we felt like we had to run a little bit more with the quarterback possibly, and that’s where I felt Ty had a really nice week and that put us in that spot,” Chesney said. “This is just one of those things that I’m sure if Madden would’ve went in there, he would have done a phenomenal job as well. But I thought Ty was the guy we decided on at this moment based on the previous week of practice.”

Chesney and Dieffebach acknowledged that the fight for the UCLA backup spot never ends.

“Every week is a battle between me and Madden for the two-spot, and I mean both of us were executing in practice,” Dieffenbach said. “… When I heard that I was [going to play, it was] just tunnel vision, just ready to go execute.”

Prior to helping earn UCLA’s first victory at Autzen Stadium since 2004, Dieffenbach spent the 2025 campaign at Cal Poly, where he started 11 games, throwing for 1,305 yards, nine touchdowns and nine interceptions, alongside 321 ground yards and four scores.

Dieffenbach’s one-year stint in San Luis Obispo was preceded by two years at Pittsburgh, where he did not see any game action. The signal caller’s transfer to UCLA marked a return to Southern California for the Agoura High product, who started his high school career as a wide receiver but finished his three varsity seasons with 4,153 passing yards and 48 touchdowns.