LOS ANGELES — Ty Dieffenbach had shown he could manage a lead.

On Saturday, he proved he could win a football game.

Making his first start after UCLA lost starting quarterback Nico Iamaleava to a potentially season-ending injury, Dieffenbach diced apart Wisconsin’s defense for 264 passing yards. He helped the Bruins (6-0 overall, 4-0 Big Ten) convert 13 of 20 third downs and score on drives of 90, 91 and 94 yards in a 17-7 victory over Wisconsin (4-2, 2-1).

He read the Badgers’ varied looks, as they periodically shifted between multiple zone coverages, and often alternated to man-to-man on third downs. He delivered touch passes over those zones and rifled balls into windows against man-to-man looks. He took the short completions the defense gave him and hit the shots when they were presented. He executed the Bruins’ game plan to stay ahead of schedule, rarely putting his offense in unmanageable down and distances.

“It was a really reassuring day for us with him and him, I’m sure, with himself, and him with his teammates,” head coach Bob Chesney said afterward.

That comment captured the poise Dieffenbach played with, the comfort he brought to the UCLA offense, and assurance he provides moving forward for a team with College Football Playoff aspirations. On Sunday, UCLA ascended to No. 9 in The Associated Press Top 25 Poll, matching its highest ranking since 2022.

He didn’t look like a backup or a Cal Poly transfer making his first FBS start.

On the Bruins’ first drive, offensive coordinator Dean Kennedy got him comfortable with two short completions to Semaj Morgan and Jalen Saint Paul. His next two completions went for chunk gains – dropping two passes over Wisconsin’s level of linebackers to Brian Rowe Jr. and Landon Ellis. Then on a third-and-6 inside the red zone, he recognized Wisconsin’s switch into man, and slotted one to Saint Paul who ran a quick in-breaker to beat his defender.

The Badgers often alternated from their normal Cover 3 and Cover 2 looks into man-to-man on third downs.

“We knew they were gonna play a lot of man on third down, which is really good for us. Our guys went out there and made a play,” Dieffenbach said. “Third down just goes to the game plan.”

It seemed as if a factor of the Bruins’ game plan was to get short gains on first and second downs and bet on themselves on third-and-manageable as they rarely faced third downs of 7 yards or longer. On the flip side, Saturday was the first time their running game truly struggled – UCLA entered averaging 253.2 rush yards per game (6th in FBS) and only rushed for 120 – which forced them into more third downs.

After settling for three on that first drive of 90 yards, UCLA found the end zone on the next two.

In the second quarter, the Bruins started from their own 9-yard line. They faced a third-and-6 from the 13, and as expected Wisconsin switched to man, so UCLA ran clear outs for an underneath route, making space for a 31-yard catch-andprun for Morgan. Two plays later, with Wisconsin going to man again on a third-and-5, Dieffenbach connected with Rowe on a deep comeback route. To finish the drive, with Wisconsin switching to man again on a third-and-5 from the 22-yard line, UCLA started in empty, motioned Saint Paul into the backfield, creating a mismatch. Dieffenbach found him on the choice route and he extended it down to the goal line, setting up Wayne Knight’s touchdown.

“His pre-snap thought process is phenomenal,” Chesney said of Dieffenbach. “His ability to see the pictures and understand the tendencies, and at the same time confirm them right before the snap, is what leads him to be able to understand exactly where the voids in the zones will live, and to deliver the ball quickly on the proper shoulder away from leverage, and I think those were all things that he just did a phenomenal job of.”

After going scoreless throughout the third quarter, UCLA needed points to put the game in hand.

As the fourth quarter loomed, Tupac Shakur and Dr. Dre’s “California Love” permeated the Rose Bowl. Dieffenbach was transported back to his childhood, sitting in those light red seats, under the San Gabriel Mountains, watching the players on his hometown team jump around on the sideline.

Except now he’s one of them, looking up into those stands to see the Calabasas and Agoura communities, and the entire UCLA fan base behind him.

“It was special to me,” Dieffenbach said.

With that support, the Bruins began the fourth quarter backed up against their end zone.

On first-and-18 from their own three, Dieffenbach identified Wisconsin’s Cover 3, and lofted an alley-oop over the flat defenders to Ellis for 28 yards. A perfectly placed pass, which would have been his best ball of the night. But, two plays later, facing a third-and-6, Wisconsin decided to stay in a zone. Dieffenbach wasn’t phased, noticing the coverage didn’t shift on pre-snap motion. He saw the Cover 2 coming and rifled one into Morgan for 33 yards.

“I saw that it was zone coverage, so I got my eyes on that safety in the middle of the field,” Dieffenbach said. “I could have driven (the throw) a little bit more, but I saw that Mike (linebacker) sitting so I banged it into Semaj.”

Anthony Woods scored two plays later, essentially securing the win for UCLA.

To hear Dieffenbach explain his reads, to see him execute them throughout Saturday’s win, should bring confidence to UCLA the rest of the way. As the Bruins traverse a favorable schedule, which includes just one team currently ranked in the Top 25 (No. 19 USC), with the hopes of qualifying for the 12-team CFP, they can rest easy with Dieffenbach.

For now, the weekly quarterback battles will quiet down. The Bruins can focus on getting their offensive line – which lost guard Eugene Brooks on Saturday after left tackle Jordan Davis was already out – and defensive back group – which was without lockdown Rodrick Pleasant – healthy.

If people who had just started thinking UCLA’s CFP hopes were realistic after defeating Oregon, returned to doubting once Iamaleava went down, they can believe again.