Cardinals vs. 49ers score: Kyler Murray outduels Trey Lance as Arizona stays unbeaten atop NFC West

It was Trey Lance time on Sunday for the 49ers, who were looking to prove they still belong in the hunt for an NFC West title. The rookie quarterback filled in for the injured Jimmy Garoppolo, but despite a strong showing as a runner, he struggled -- and, ultimately, failed -- to deliver through the air in a day that started in the Cardinals' favor. MVP candidate Kyler Murray chucked it up with success early on, and while he slowed down after the break thanks to some tough shots from the Niners' defense, his play-making still lifted Arizona at home, giving the Cardinals a 17-10 victory to improve to 5-0.

Here are some takeaways from Arizona's fifth straight win:

Why the Cardinals won

On a day that was always going to be tough for Trey Lance, making his first career NFL start on the road, they started fast, building a 10-point lead that stood for the entirety of the contest. Their momentum really plateaued after Kyler Murray took a few shots and San Francisco seemed to figure him out in the pocket, but his backyard style worked out of the gate, with Rondale Moore in particular flashing as both a runner and receiver. The defense was physical with Lance all day, letting him rumble on the ground but never consistently succeed through the air. Budda Baker's early pick was especially damaging for the 49ers' early chances, and then Murray came through on the other side of the ball following a late fourth-down stop (one of a whopping four on the day), hitting DeAndre Hopkins on a precision pass in the red zone to seal the win.

Why the 49ers lost

Remember all the talk about how Trey Lance would revitalize Kyle Shanahan's offense? Well, the rookie definitely gave it all, putting his body on the line in a never-say-die rushing performance that helped Elijah Mitchell and Deebo Samuel also find space with the ball in their hands. But as a passer, he was not nearly as effective, struggling on everything from short to deep shots -- some of them influenced by interior pressure, some of them the byproduct of an excitable run-first approach. The Niners simply couldn't do much of anything through the air. And while their defense was surprisingly stout for much of the contest, limiting the Cardinals' rushing attack and keeping Murray in check for the better part of a half, it couldn't quite lock down deep shots to Hopkins and Moore in a game that demanded near-perfection.

Turning point

The Cardinals came out roaring, picking off Lance on their first defensive series, then scoring with ease (and speed) to go up 7-0. But then the 49ers drove 12 plays all the way to Arizona's 1-yard line, and faced with a fourth-and-goal, dialed up a chance for Lance to push it in. Rolling out to his right, he looked to have the space to get in, but instead got walloped at the 1 by a slew of Cardinals defenders. The turnover on downs left San Francisco with zero points despite a huge drive and allowed Arizona to go up 10-0, putting the Niners in a hole they could never dig out of.

Play of the game

Give it to the Cardinals, who rallied to Lance with so much speed and intensity that they delivered one of the most physical fourth-down goal-line stops in recent memory:

What's next

The Cardinals (5-0), who remain the NFL's last unbeaten team, will hit the road in Week 6 for a cross-conference showdown with the Browns (3-2). The 49ers (2-3), meanwhile, will rest up during their bye before returning in Week 8, perhaps with Jimmy Garoppolo back under center, against the Colts on Oct. 24.