GLENDALE, Ariz. -- Bruce Arians watched Todd Gurley's second-half NFL coming-out party and proclaimed him "a heck of a back."
Gurley saw his most extensive action as a pro and his 52-yard run set up what was the winning touchdown.
"It is just football," he said, shrugging off the performance. "I have played it my whole life and you ready your keys and study the game and everything will slow down for you."
"You're not going to win many games kicking field goals in the red zone and losing the turnover battle," Arians said, "especially in our division."
The bad outweighed the good, Arians said. "He played like a rookie today," the coach added.
"Every time we are in the red zone, we don't let nobody cross into the end zone," cornerback Janoris Jenkins said.
It was only the fourth loss in the Cardinals' 19 home games under Arians, and Palmer lost for the first time in 10 starts. He completed 29 of 46 passes for 352 yards with one touchdown and one interception.
Gurley, who was delayed in his pro debut by a knee injury, gained 9 yards in six carries in his debut last week against Pittsburgh and had 5 yards on three attempts in the first half Sunday.
"Last week was tough on him," said Tavon Austin, who had two touchdown catches. "He came out this week and exploded."
With the Rams clinging to a 17-15 lead, Gurley burst through the line and broke a couple of tackles for a 52-yard gain to the Arizona 16, and Foles threw 12 yards to Austin and the lead was 24-15 with 8:16 to play.
Gurley could have had more, but slid to the ground to help run out the clock late.
The Cardinals finally got their only touchdown when Palmer lofted a 19-yard pass to Johnson for the score that made it 24-22 with 4:38 left.
Johnson, who had a 108-yard return on the opening kick two weeks ago, brought it out again to open this game. At about the 15-yard line, Mark Barron knocked the ball loose and Daren Bates jumped on it for St. Louis at the Arizona 13. On third down from the 12, Foles threw over the middle to Austin, just the Rams' seventh touchdown of the season, and Arizona trailed for the first time this season.
Copyright 2015 by The Associated Press