The Cardinals had won three straight entering Sunday's game, and a victory would have made them 5-2, their best record after seven games since 1976.
It also would have increased their lead in the NFC West to two games, because both the 49ers and Seahawks lost.
Instead, the Cardinals dropped to 4-3 and their lead over the 49ers remained at one game.
The loss was especially disappointing because it came only a week after the Cardinals beat the Giants in the Meadowlands.
Some were calling that the team's most important road victory since it moved to Arizona in 1988. That's debatable, but there's no question the loss to the Panthers brought the Cardinals back down a peg.
"These are the kinds of games, after big wins, that you have to come back with the same intensity," quarterback Kurt Warner said. "I've played a long time with a lot of different teams and it's a hard thing to do. We just didn't bring our 'A' game."
--The Cardinals are 1-3 at home after going 14-4 there the previous two seasons under coach Ken Whisenhunt.
"These are games that we're supposed to win and games that can come back and bite you in the end," defensive end Darnell Dockett said after last Sunday's 34-21 loss to Carolina. The Cardinals have played only one good half at home all year, against Houston
"We haven't protected our house at all this year," said nose tackle Bryan Robinson. "We had to do a goal line play against Houston to win that game. We're out of sync right now."
--WR Anquan Boldin passed Larry Centers to become the franchise's all-time leader in receptions with 537. Centers had 535. Boldin is hobbled by an ankle sprain and could use a week off to recover.
"The one issue we had going into the game was if he took a shot on that ankle," coach Ken Whisenhunt said. "As low of probability of that happening, it did happen. It's hard when you lose him in the game because you only have so many receivers that are active. That's what makes it difficult."
--QB Kurt Warner wasn't beating himself up after throwing five interceptions and losing a fumble in the loss to Carolina.
"It's one of those games where it just seemed like every time the ball was bouncing somewhere it went into their hands," Warner said. "It's to their credit. They were hustling."
--The Cardinals gave up 270 yards rushing. The team's media guide lists the top four rushing games by an opponent and in fourth place is New Orleans that had 272 yards in 1983.
"I don't think we got exposed," said defensive tackle Darnell Dockett. "I think they just outplayed us, offense and defense. I'm just shocked that we lost, period. I don't care about no rushing yards. They could have had 1,000 rushing yards and we won. That would have been better for me."
STRATEGY AND PERSONNEL
--WR Anquan Boldin likely will be questionable this week with a sprained right ankle. Boldin aggravated the injury against the Panthers in the third quarter and didn't return.
--RB LaRod Stephens-Howling scored his first NFL touchdown on a 13-yard swing pass. The club is trying to work Stephens-Howling into the role as third-down back and this is the first time he's shown some breakaway ability.
--DE Darnell Dockett aggravated a right ankle sprain but continued to play. Dockett isn't 100 percent but he's never missed a game since entering the NFL in 2004.
--CB Dominique Rodgers-Cromartie's lack of experience is going to crop up from time to time. He was beaten by Steve Smith for a 50-yard touchdown on a stop and go move.
--FS Antrel Rolle played the entire game against Carolina despite practicing only one day last week because of a foot injury.