San Francisco's starting quarterback was hit hard four times in his first three drives and struggled to build rhythm with his wideouts before his fourth and final march led to success.
Kaepernick started his last series 5-of-5 passing with completions to five different targets before his final two throws were deflected at the line, forcing San Francisco to settle for a Phil Dawson field goal.
Nobody does a better job with quarterbacks than coaches Jim Harbaugh and Greg Roman, but after seeing the 49ers struggle mightily in last week's 34-0 wipeout against the Broncos -- and again on Sunday -- it's fair to wonder when this reloaded passing game will take off.
Maybe next week, with Harbaugh confirming that Kaepernick and the starters will see time in San Francisco's fourth and final preseason tilt.
Here what else we learned from Sunday's two-game slate:
1. While Kaepernick was hot-and-cold, Philip Rivers caught fire and never looked back. The Chargers passer ripped off a 9-of-10 day for 85 yards with a 10-yard touchdown strike to tight end Antonio Gates. Rivers was impressive, seeing the field well, cycling through his progressions and making wise decisions. Last week's loss to the Seahawks was ghastly, but San Diego's signal-caller has burned bright in two of his three preseason tilts.
2. The pressure on Kaepernick showcased a Niners line that failed to contain the Chargers. The absence of holdout guard Alex Boone didn't help, but his replacement on the right side, Joe Looney, fared better than left guard Mike Iupati, who lost too many matchups.
4. Get this: Blaine Gabbert threw San Francisco's first touchdown pass of the preseason, a six-yard bullet to tight end Vance McDonald. Kaepernick's radioactive backup finished the first half 6-of-8 passing for 63 yards with the score and a quarterback rating of 137.0. I promise this is real.
-- Marc Sessler
1. Carson Palmer was not sharp in his final tune-up before the regular season. The veteran quarterback missed an easy touchdown throw to Michael Floyd on Arizona's first drive, then threw a pick six to Bengals cornerback Terence Newman on the team's following possession. "We missed some wide open guys," Bruce Arians verified to NBC's Michele Tafoya.
2. Bengals All-Pro defensive tackle Geno Atkins looked tentative in his first action since tearing his ACL last November. Atkins played one series and was pushed around by Cardinals guard Ted Larsen. A reminder that having Atkins back for Week 1 doesn't necessarily mean the Bengals will have the force of nature they remember. At least not yet.
3. Larry Fitzgerald looks like his old self. The wide receiver had a diving 23-yard grab and a "My hamstrings feel fine!" 43-yard catch-and-run. Fitzgerald and Floyd are the sneaky dark horse candidate to be the NFL's top wide receiver duo in 2014.
-- Dan Hanzus