With Vernon Davis sidelined by injury, the 49ers' offense sputtered in the second half of a 10-9 loss to the Carolina Panthers at Candlestick Park on Sunday.
Davis left the game with a concussion late in the first half and the 49ers were held to 61 yards of offense in his absence in seeing their five-game winning streak end.
"Vernon changes defenses," Niners quarterback Colin Kaepernick said. "He makes them adjust differently, he makes them do things they don't normally do. He's a big loss."
After falling behind 9-0 in the first half, the Panthers (6-3) grabbed a 10-9 lead when kicker Graham Gano nailed a 53-yard field goal with 10:45 remaining in the fourth quarter. But there was no comeback as the 49ers picked up only 8 yards and one first down on their last three possessions.
Kaepernick threw for 91 yards - a career low as a starter - completing 11 of 22 passes. He also threw an interception to Panthers linebacker Drayton Florence on the Niners' final play of the day.
"They're a good defense," Kaepernick said. "But today was more our lack of execution than what they were doing."
Niners wide receiver Anquan Boldin downplayed the impact of Davis' injury.
"It didn't change anything," he said. "We got exactly what we saw on film -- we just didn't execute."
The 49ers (6-3) capitalized on a pair of Panthers miscues in the first half, jumping ahead 9-0 with less than seven minutes to play in the second quarter.
Already up 3-0, the offense took advantage of a short field in the second quarter after a partially blocked Andy Lee punt hit Florence downfield and rookie Eric Reid recovering, giving the 49ers possession at the Panthers 41.
After picking up a first down, Phil Dawson kicked a 43-yard field goal, putting the 49ers ahead 6-0.
Dawson added a 25-yard field goal later in the quarter after Tremaine Brock returned a Cam Newton interception 41 yards to the Panthers 24-yard line.
It was the 15th straight takeaway that the 49ers have converted into points this season (nine touchdowns, six field goals) and Brock's fourth interception of the year.
The drive stalled when coach Jim Harbaugh elected to take a delay of game penalty on fourth-and-1 from the Panthers 2 after Davis left the game with a concussion two plays earlier.
Harbaugh said the absence of Davis and backup tight end Garrett Celek, who left the game with a hamstring injury, factored in to his decision.
"Both Celek and Davis were out and we needed some time to move some personnel around to accommodate that situation," he said.
The defense almost forced another turnover on the next Panthers possession when Newton floated a pass into the hands of linebacker NaVorro Bowman near the 49ers 35-yard line. But instead of intercepting the pass, the ball deflected off Bowman's fingers and landed in the hands of Panthers tight end Greg Olsen at the 49ers 27.
DeAngelo Williams took a quick inside handoff into the end zone on the next play, cutting the 49ers' lead to 9-7 with 1:59 remaining in the first half.
Prior to the drive, the 49ers had limited the Panthers to 30 yards of offense.
"Them scoring that touchdown made the difference," Niners linebacker Patrick Willis said.
The Panthers eventually jumped ahead in the fourth quarter after former 49ers wide receiver Ted Ginn Jr. gave his team possession at their 45-yard line, returning a punt 24 yards.
After picking up a first down, Graham, who missed a 48-yard field-goal attempt earlier in the half, split the uprights on a 53-yard try.
The Panthers' defense sacked Kaepernick six times while holding the NFL's top rushing attack to 25 yards in the second half.
Dawson opened the scoring with 52-yard field goal on the 49ers' first possession of the game.
Linebacker Aldon Smith played 11 snaps in his return to the 49ers' defense after five-week hiatus to treat substance abuse following an arrest, helping the unit hold Newton to 169 passing yards and 17 rushing yards.
"Aldon came back and got his feet wet," Willis said. "I'm sure he'll gradually get back even more."
Mario Manning made his season debut with the offense, catching three balls for 30 yards.
The 49ers also lost Reid, a safety, to a concussion and defensive lineman Ray McDonald to an ankle injury.
"Eric has been some amazing football for us," Willis said. "To see him go down today, it's unfortunate and I pray that he'll be OK."