Finer Carolina

If there was any doubt, Carolina sent San Francisco an emphatic message in a 10-9 victory at Candlestick Park on Sunday that left the beat-up Niners without three key starters and raised questions about just how good the defending NFC champions are in 2013.

For the third straight time dating to Week 2, Colin Kaepernick and the 49ers’ offense were rendered punchless against a team with a winning record.

In the latest unsightly performance, the 49ers (6-3) had 46 net passing yards – their fewest since Alex Smith’s first NFL start, Oct. 9, 2005 – collected 10 first downs, and had four punts and two turnovers in a scoreless second half.

Wide receiver Anquan Boldin twice termed the display “unacceptable.” “We didn’t get it done,” he said.

The 49ers collected 151 net yards, their fewest since they had 133 in a win over theVikings on Nov. 5, 2006. Did Carolina, which has allowed the second-fewest points in the NFL , have anything to do with the offensive ineptitude?

Boldin shook his head: “That’s all on us,” he offered.

Said quarterback Colin Kaepernick: “They’re a good defense. But today was more our lack of execution than what they were doing.”

Others, however, might wonder, given San Francisco’s performance against the NFL’s better teams. In the 49ers’ five-game winning streak that preceded Sunday’s game, they scored 30 or more points in each game for the first time since 1997. That streak came against opponents with a 16-30 record, and none of those teams had a winning record when playing the 49ers.

In their three losses – to Seattle (9-1), Indianapolis (6-3) and Carolina (6-3) – the 49ers have averaged 5.7 points and Kaepernick has committed seven turnovers and posted a 35.0 passer rating. The combined score in those losses: 66-19.

It was pointed out to center Jonathan Goodwin that a pattern is developing.

“I’ve got a lot of faith in this team,” Goodwin said. “Who we’ve beat, their records, we have no control over that. But I definitely have a lot of confidence in this offense. This team. Unfortunately, we have lost to the teams with the better records, but that doesn’t bother me one bit.”

The 49ers were certainly bothered by the loss of tight end Vernon Davis, who exited with a concussion with seven minutes left in the second quarter. Two plays after Davis exited, the 49ers took a 9-0 lead on a 25-yard field goal by Phil Dawson.

In the final 37 scoreless minutes without Davis, San Francisco had five first downs and 65 net yards. The 49ers were also without Davis in a 27-7 loss to Indianapolis on Sept. 22.

“Vernon changes defenses,” Kaepernick said. “He makes them adjust differently. He makes them do things that they don’t normally do. He’s a big loss.”

Defensive tackle Ray McDonald (ankle) didn’t play in the second half, and safety Eric Reid exited in the third quarter with his second concussion of the season. In addition, tight end Garrett Celek (hamstring) was injured early in the first quarter, leaving the 49ers with one tight end – rookie Vance McDonald – after Davis went to the locker room.

Despite the laundry list of injuries – and the inert offense – San Francisco entered the final quarter with a 9-7 lead, thanks to its stout defense. The Panthers managed 15 first downs, 250 yards and quarterback Cam Newton had a 52.7 passer rating, but they took a lead they wouldn’t relinquish on Graham Gano’s 53-yard field goal with 10:05 remaining.

Carolina produced the game’s only touchdown in the second quarter on the first play after the two-minute warning when DeAngelo Williams scored on a 27-yard run on which he broke the attempted tackles of three 49ers.

“Both defenses played well,” inside linebacker NaVorro Bowman said. “We as a defense can’t control anything that’s going on on the other side of the ball. That’s the stressful part about having a good game, knowing you are playing well. You can’t control the other side. … They struggled today. They will go back to the drawing board and do better.”

Kaepernick (11-for-22, 91 yards) was sacked six times, but had a chance to lead a game-winning drive. The 49ers took possession at their 20-yard line with 1:02 left, but he tossed a game-sealing interception to cornerback Drayton Florence on a play in which receivers Kyle Williams and Mario Manningham ended up a few yards apart 20 yards downfield.

The loss dropped the 49ers 2 1/2 games behind Seattle in the NFC West and there’s no cupcake up next. San Francisco will visit the Saints (7-2) on Sunday.

“We’ll do what we do, bounce back,” head coach Jim Harbaugh said. “Regroup, reorganize and come back this week.”