Column: NFL Week 9: AFC West? NFC West? More like AFC and NFC Worst this week

Welcome to the mild, mild West.

San Diego? Humiliated by a 37-0 defeat at Miami.

Denver? Humbled by a 43-21 loss at New England.

Seattle? Hard-pressed to land the knockout punch against winless Oakland before winning, 30-24.

And San Francisco? Huh? Quarterback Colin Kaepernick fumbled at the goal line on his team’s final play Sunday as the 49ers lost at home to last-place St. Louis, 13-10.

The Arizona Cardinals are the only reliable winners in the West — and who would have believed that? — continuing their roll with a 28-17 victory at Dallas, winning for the 14th time in their last 17 games.

They might not have needed one, but the Cardinals caught a break against Dallas, getting Brandon Weeden at quarterback instead of Tony Romo, sidelined with a back injury.

“This is a very good team,” said Cardinals quarterback Carson Palmer, whose 7-1 team has the NFL’s best record. “We feel like we can play with anybody.”

Yes, the Cardinals can play with anybody. Meanwhile, everybody is toying with San Diego. The Chargers have lost three in a row, and Sunday’s defeat was embarrassing — the club’s first shutout loss since 1999. Miami has won four of five.

“For 60 minutes, they wore us out,” said Chargers quarterback Philip Rivers, although there’s little evidence the Chargers were even on the field for a whole 60 minutes.

Then there was the familiar Peyton Manning-Tom Brady showdown, the 16th meeting between those future Hall of Famers. For Manning, it was anything but a sweet 16, especially with the New England crowd’s singsong chant of “Bra-dy’s bet-ter!”

“I don’t usually stink,” Manning said. “But I stunk today.”

Brady threw for 333 yards and four touchdowns, leading his team to a 22-point victory that snapped Denver’s four-game winning streak.

From the Insult to Injury file: Brady pushed his career passing total to 51,541 yards, moving past Broncos Hall of Famer John Elway (51,475) for fifth place on the all-time list.

Since losing by 27 points to Kansas City in Week 4, and being largely written off as yesterday’s news, the Patriots have won five in a row, with four of those being blowouts.

Seattle was the only West Coast team to win Sunday, and the defending Super Bowl champions got a scare from a Raiders franchise that has lost 14 in a row. The Seahawks won by six, but Oakland kept things interesting the whole way, almost recovering an onside kick in the waning moments.

St. Louis, meanwhile, has beaten heavily favored Seattle and San Francisco in the last three weeks.

Kaepernick, playing behind a rookie center because of injuries, was sacked a career-high eight times. The Rams got six of those in the first half, doubling their season sack total to that point.

But it was the final play that people will remember. After driving his team 88 yards in three minutes to bring it to the brink of victory, Kaepernick fumbled on a third-down sneak from the one-yard line with two seconds remaining. The Rams recovered in the end zone and held on for a three-point win. It was the second consecutive loss for the 49ers, who were coming off a defeat to Denver.

Trailing Arizona by three games in the NFC West, the 49ers won’t catch a breather this week. They play at New Orleans, which has won two in a row and will have had 10 days’ rest since winning at Carolina on Thursday night.

With the Cardinals cruising and Seattle hanging on, San Francisco’s margin for error is dwindling by the week.

To put it mildly.

On the Mark

Philadelphia backup quarterback Mark Sanchez stepped up in a big way Sunday after starter Nick Foles suffered a shoulder injury while being driven into the ground in the first quarter.

Sanchez sat out the entire 2013 season with the New York Jets after suffering a torn labrum in his right shoulder in training camp. He last played on Dec. 30, 2012.

But Sanchez certainly didn’t look rusty Sunday. On his first play, he connected with Jeremy Maclin on a deep ball for a 52-yard gain. Five plays later, he threw a strike to Jordan Matthews for an 11-yard touchdown.

“He’s good,” Eagles running back LeSean McCoy said of Sanchez, a former Jets first-round pick from USC. “Even when he came here it’s hard to look at him as a backup because of [the] success he’s had and experience. I think today wasn’t really something surprising to the team.”

It wasn’t a flawless game by Sanchez. He forced some passes and had two interceptions to go with his two touchdowns in the Eagles’ 31-21 win at Houston. But overall he played well.

The heat was already on Foles, who came into the game with nine interceptions and saw a 10th run back for a touchdown Sunday.

Foles suffered a broken collarbone, according to multiple reports, an injury that would sideline him for at least several weeks. In addition, the Eagles have to deal with the loss of linebacker DeMeco Ryans, the centerpiece of their defense. After making an interception, Ryans suffered an ankle injury and fumbled the ball. Later, it was reported he’d sustained a torn Achilles’ tendon, almost certainly a season-ending injury.

A feat of the feet

Three quarterbacks in the last 25 years have had runs of at least 20 yards in four consecutive games. Steve Young, Michael Vick . . . and Ryan Tannehill.

Tannehill joined those two Sunday, rushing for 47 yards in four carries, including a 22-yarder. He’s a former college receiver, and burned the Chargers more than once on read-option plays.

Come on back

The comeback-player-of-the-year field is looking more competitive by the week.

Philadelphia’s Maclin, who missed the entire 2013 season with a knee injury, had six catches for 158 yards and two touchdowns Sunday. A week earlier, he had 12 catches for 187 yards and two touchdowns in a loss at Arizona. He’s the first player in Eagles history with at least 150 yards receiving and multiple touchdown catches in consecutive games.

New England’s Rob Gronkowski, who missed all but seven games last season, had nine catches for 105 yards and a touchdown in the victory over Denver. In last week’s win over Chicago, he had nine catches for 149 yards and three touchdowns.

Houston running back Arian Foster, who missed half of last season, saw his four-game streak of 100-yard rushing games come to an end with a 56-yard performance against the Eagles, but he also scored on a 56-yard catch and carry.

Second thoughts

San Francisco running back Marcus Lattimore, who returned to practice last week after sitting out two years recovering from a severe knee injury he suffered in college, might not be returning at all.

Lattimore reportedly is deciding whether he wants to continue his comeback attempt.

He was not on the sideline during Sunday’s game against the Rams.

“Did not see Marcus,” 49ers Coach Jim Harbaugh said. “I’m sure we’ll have an announcement about that.”

Back on the horse

Surely it was of no consolation to him after losing at New England, but Manning’s two touchdown passes kept one streak alive. He has thrown for multiple touchdowns in an NFL-record 14 consecutive games, and tied one of his football heroes, Johnny Unitas, for the third-longest streak with at least one scoring pass (47 games).

“I thought we were just pretty dead average on offense, I thought I was very below average, didn’t play well,” Manning said. “So that’s all I can speak for, is really me. I’ve got to play better. I’ve got to do that starting next week.”

The Broncos play at Oakland on Sunday.

Stuck in double digits

Dallas running back DeMarco Murray rushed for 79 yards in 19 carries, which is respectable, especially against an Arizona defense that came into Sunday’s game having allowed a league-best 3.3 yards per carry.

But it was the first time this season that Murray was held to fewer than 100 yards.

“I thought we did good against nine guys in the box,” Murray said. “It was the hardest day. You got to give those guys credit, a really, really good front seven. . . . That was probably the first time we have seen [that many in the box]. I am sure it won’t be the last.”

Arizona’s Calais Campbell said slowing Murray was just a matter of “want-to” on the part of the Cardinals defense.

“Coach challenges us,” Campbell said. “Told us to keep him under 100. We took it personal and we went out there and did what we had to do.”

To break Eric Dickerson’s single-season rushing record of 2,105 yards, Murray would have to average 139 yards in the final seven games.

sam.farmer@latimes.com

Twitter: @LATimesfarmer