SAN DIEGO — First the San Diego Chargers’ Keenan Allen wore the goat horns. Then teammate Marcus Gilchrist was fitted for them.

But in San Diego’s thrilling 27-24 win over the St. Louis Rams on Sunday, Allen and Gilchrist flipped their status.

Allen muffed a third-quarter punt that breathed life into the Rams’ rally. But later the wide receiver caught a 29-yard, fourth-quarter pass from Philip Rivers to give the Chargers their final points.

And Gilchrist, a safety who was beaten on wide receiver Stedman Bailey’s late touchdown catch, ended up with a game-saving interception, picking off a Shawn Hill pass at the Chargers’ goal-line with less than a minute remaining.

“It came down to who was going to make a play,” Chargers coach Mike McCoy said.

With the win San Diego (7-4) tied the Kansas City Chiefs for second place in the AFC West.

The Rams (4-7) failed to follow up on last week’s upset of the Denver Broncos.

Chargers running back Ryan Mathews, who missed seven games this season because of injuries, rushed for a touchdown and game-high 105 yards.

“You never know how much you miss a guy until he gets back,” said Chargers quarterback Philip Rivers, who was 29 of 35 for 291 yards and a touchdown, with an interception.

Hill struggled, completing only 18 of 35 passes for 198 yards, a touchdown and two interceptions. The killer pick was on his last pass of the game.

What the Rams said:

“We have to learn that until we put a couple in a row together, it’s going to always be hard for us.” — Rams coach Jeff Fisher, on his team failing to win consecutive games this season.

What the Chargers said:

“The only statistic that matters is that one important stat: a win.” — LB Dwight Freeney, on the Chargers overcoming numerous mistakes to defeat the Rams.

What we learned about the Rams:

1. Good teams find a way to win and then there’s the Rams. For the third straight time, the Rams failed to follow up a big win with another win. Yes the Rams have beaten the Seahawks, 49ers and Broncos but they can’t string together consecutive wins. Quarterback Shaun Hill was inserted into the lineup because he takes good care of the football. But then this game became loss No. 7 because he tried to force a pass into double coverage with a minute to play and the Rams poised to score. The Rams aren’t bad; they just aren’t good and they proved it again on Sunday.

2. Just because the element of surprise is a bit shredded, the Rams will still pull into their bag of tricks on special teams. The Rams have been featured numerous times this season when pulling the wool over someone’s eyes on special teams. And at a critical juncture on Sunday, the Rams line up for a punt then hoodwinked the Chargers when Johnny Hekker found Bailey for a 19-yard reception and a first down that kept a scoring drive alive. Sleep on the Rams, when they line up for special teams, at your own risk.

–LB Alec Ogletree led the Rams with nine tackles, eight of which were solo. It’s the second straight week he has led the team in tackles — he had 13 tackles against the Broncos.

–CB Janoris Jenkins’ 99-yard interception return for a score tied for the second longest ever against the Chargers. Jenkins also had a forced fumble and another pass defensed, along with four tackles.

–RB Tre Mason couldn’t quite duplicate his showing last week when he rushed for 113 yards in the upset over Denver. But Mason, a rookie, still rushed for nearly 4.0 yards per carry, finishing with 62 yards, with a long of 21. His 16 carries were 13 fewer than he had last Sunday.

What we learned about the Chargers:

1. Ryan Mathews gives the Chargers a big-play element that none of the other backs can. He proved it on a 32-yard touchdown run, on his way to his first 100-yard rushing game of the season. “You never know how much you miss a guy until he gets backs,” quarterback Philip Rivers said. Mathews did have to go into the locker room at one point, with indications are he received a shot for a sore shoulder. But he returned to action late in the fourth quarter.

2. Another game, another audition for a center. Since Nick Hardwick went on IR, the Chargers have gone through centers at an alarming rate. Rookie Chris Watt made his first NFL start on Sunday, and he showed he’s up to the task as the Chargers’ fourth starting center on the season. Philip Rivers was sacked three times, but two of those were of the coverage variety and once Rivers just took a sack instead of having an incomplete pass. Watt was clean in calling out the blocking assignments, which was a big deal when facing the Rams rush.

–S Jahleel Addae was inactive as he has yet to play since being concussed on Oct. 23. Addae is practicing.

–WR Keenan Allen had a touchdown catch but also a tackle when he muffed a punt. He still has one more tackle (three) than scoring receptions (two).

–S Darrell Stuckey played more in passing packages with the injury to Jahleel Addae forcing him out of the lineup. But Stuckey’s biggest contributions come on special teams — where he’s a captain — and he proved it by blocking the Rams’ field-goal attempt in the second quarter. He also added three tackles.