ST. LOUIS (AP) Two running backs down, the Arizona Cardinals kept the production sky high.
Rookie David Johnson ran for 99 yards and scored a touchdown in his first career start, helping pave the way for a decisive 27-3 victory over the St. Louis Rams on Sunday. Coach Bruce Arians said the third-round pick from Northern Iowa reminded him of a young Edgerrin James.
''Exactly what I expected,'' quarterback Carson Palmer said. ''He doesn't act like a rookie, he doesn't look like a rookie.''
Johnson caught one of Palmer's two TD passes as Arizona (10-2) rolled up 524 yards in its sixth straight win. Fellow fill-in Kerwynn Williams scored his first career TD on a 35-yard run, and the Cardinals had 175 yards rushing. They remain three games ahead of the Seahawks in the NFC West.
Johnson stepped up after injuries to Chris Johnson and Andre Ellington. He admitted to being nervous - but just the first series.
''After that I started getting more comfortable and seeing the holes opening,'' Johnson said. ''Felt like college days where I got a chance to help out my team.''
The Cardinals might need Johnson again on short notice, with the next game on Thursday at home against the Vikings. Johnson entered with just 139 yards rushing on the year.
''That's going to be new to me,'' he said. ''I'll hurry up and try to recover, get in that cold tub.''
Palmer was 26 of 40 for 356 yards with no interceptions and - unlike the previous three games in the streak - he did not need to lead a late scoring drive to win. Arizona led 10-0 at the half and never let the Rams into the game.
Larry Fitzgerald made his 1,000th reception and topped 1,000 yards receiving for the seventh time. The Cardinals (10-2) have won seven of eight since losing 24-22 at home to St. Louis in Week 4.
At 32 years, 97 days, Fitzgerald is the youngest player to reach 1,000 catches and is tied for 10th on the career list with Hines Ward. He caught eight passes for 55 yards.
''It's nice, but it's even better to have three consecutive seasons with 10 wins,'' Fitzgerald. ''To be here for that long and see that complete transformation, it makes you feel proud to be a part of it.''
The Rams (4-8) have lost five in a row and have been outscored 58-10 the last two. The team announced 51,115 tickets distributed, a season low and about 15,000 shy of a sellout, and the dome looked half empty.
''It's easy to put your head down and just give up,'' said quarterback Nick Foles, who passed for just 146 yards and threw his fourth interception in two games. ''I know that's not what I'm going to do.''
Coach Jeff Fisher said Case Keenum, symptom-free from a concussion and the backup on Sunday, would start next week against Detroit.
''It's kind of a broken record thing with the offense,'' Fisher said. ''We've got to get it fixed.''
The Cardinals drove 80 yards on the opening drive capped by rookie J.J. Nelson's 22-yard scoring catch. They dominated in time of possession, hold the ball for 39 minutes and 47 seconds.
Williams replaced David Johnson on kickoffs and fumbled out of bounds, but redeemed himself on the scoring run that put Arizona up 24-3 late in the third.
Williams' TD was the third long play on that drive, with a 31-yard catch by Michael Floyd and 23-yard run by David Johnson coming on successive plays.
The Rams were shut out in the first half for the second time this season. They finished with 212 yards and nine first downs, going 1 for 12 on third down.
Two Rams, cornerback Janoris Jenkins and tight end Lance Kendricks, were ruled out with concussions late in the game. Jenkins was evaluated twice, both times on hits from teammates, and didn't recover from blow delivered by Mark Barron on Johnson's 10-yard TD catch with 5:51 to go in the third.
Notes: Palmer has 29 touchdown passes, one shy of the franchise record set by Kurt Warner in 2008. ... Sixteen Cardinals have scored, most in the NFL. ... Johnson and Hall of Famer Gale Sayers are the only rookies in NFL history with four rushing TDs, four receiving TDs and a kickoff return TD. ... Rams replacement K Zach Hocker strained a quad before kickoff so P Johnny Hekker handled kickoffs for the first time since high school. Hocker made a 35-yard field goal.
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