49ers squander early lead vs. Chargers, fall to 1-3 after Week 4 loss

The San Francisco 49ers got off to a hot start on the road against the Los Angeles Chargers in Week 4. But a 14-0 lead quickly evaporated, and both injuries and costly mistakes doomed the Niners in their 29-27 Week 4 loss.

It certainly looked like the San Francisco 49ers were going to pull off a massive upset on the road against the Los Angeles Chargers in Week 4. Especially after fill-in defensive back Antone Exum intercepted Chargers quarterback Philip Rivers for a pick-six touchdown on L.A.'s first offensive possession of the game.

San Francisco took a 14-0 lead that quarter after quarterback C.J. Beathard found wide receiver Kendrick Bourne for a two-yard touchdown pass. And while the Chargers made it a one-score game late in the quarter, kicker Caleb Sturgis' issues with finding the uprights continued.

That early momentum evaporated in the second quarter, though, as L.A. managed to roar back against a Niners defense that no longer displayed the early prowess and urgency seen the previous frame. Rivers hit running back Austin Ekeler for a 22-yard touchdown pass, and the 49ers' pass-rushing woes continued to be a massive problem throughout the contest.

Injuries too.

Wide receiver Dante Pettis was lost to a knee injury on his first punt-return attempt and didn't return. Left tackle Joe Staley also exited with a knee injury, and the Niners were without fellow tackle Mike McGlinchey for a short period too. No. 1 running back Matt Breida, who was listed as questionable before the game with a knee injury, also was hurt in the fourth quarter.

L.A. managed to tie things up at 17 by halftime, which seemed to be OK enough for head coach Kyle Shanahan and Co. to handle. After all, the Niners were to start the second half on offense. But San Francisco went 3-and-out, the Chargers marched down the field and scored a touchdown with running back Melvin Gordon (Sturgis missed the extra point) and gained both the lead and momentum in the process.

If that hurt, the end result of the 49ers' next possession was a dagger.

Beathard and the Niners were driving effectively enough, making it into the red zone and taking advantage of a number of Chargers penalties. But on 1st-and-goal from the Chargers' 8-yard line, Beathard attempted to hit tight end Garrett Celek, who couldn't contain the pass, which flew into the hands of Chargers cornerback Trevor Williams.

And all Williams had to do was return it 86 yards the other way:

A back breaker.

Yet the Chargers managed just a field goal off the play. And after Beathard hit tight end George Kittle for an 82-yard touchdown in the third quarter, the Niners found themselves trailing by just two points.

A whole new ballgame, although one might have questioned Shanahan's desire to go for points late in the first half instead of running out the clock.

The 49ers managed to retake the lead early in the fourth quarter, following a scary hit on Beathard, who was valiantly trying to get to the first-down marker on a quarterback scramble. He didn't get it, but at least the Niners were able to retake the lead, only to give it back after the 49ers missed more tackles on Gordon's long run that led to a Sturgis field goal.

Backed up within their 10-yard line, the 49ers faced a two-point deficit with just shy of four minutes remaining and only one timeout. Despite a promising start to the drive, Beathard felt pressure from safety Derwin James and tried to pass, only to see his attempt somehow wind up in the hands of rookie defensive end Isaac Rochell.

The Niners had their share of chances. But ultimately, they committed far too many mistakes and had more issues with missed tackles.

San Francisco now falls to 1-3 and gets to host the winless Arizona Cardinals in Week 5.