Rookie running back David Johnson gave the Arizona Cardinals a bit of everything in his fourth game.

The problem for Johnson was that the bad outweighed the good as the Cardinals were knocked from the ranks of the unbeaten with a 24-22 home loss to the St. Louis Rams. Although he scored on a 23-yard reception late in the the fourth quarter to keep his team's hopes alive, Johnson made a pair of huge mistakes early in the contest.

The third-round draft pick out of Northern Iowa fumbled the opening kickoff of the game and Arizona converted it into a quick touchdown, marking the first time in four games that the Cardinals trailed.

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"It was the ball in the wrong hand," Johnson said of the miscue. "A kindergarten thing. Had the ball on the inside, should have had it on the outside. He just hit the ball on the right spot and it came out."

Johnson dropped a sure touchdown pass later in the first quarter and the Cardinals had to settle for the first of five field goals by Chandler Catanzaro. Still, coach Bruce Arians had Johnson in the game at crunch time and he delivered with four catches for 63 yards.

"He came back big for us," defensive end Calais Campbell said. "Had a big catch for a touchdown. He's going to be a big player in this league for a long time to come."

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