Upset is a bolt from the blue for Philip Rivers, Chargers

Philip Rivers hadn’t even reached the airport after Sunday’s game in Kansas City, and already his spirits had climbed to 35,000 feet. The San Diego quarterback said he was calling from the team bus, although it sounded closer to cloud nine.

“This is one of those games you’ll never forget,” the elated cellphone Charger said as teammates hollered and laughed in the background, basking in the afterglow of a 41-38 upset of the Chiefs.

Rivers clinched the victory with a 26-yard touchdown pass to receiver Seyi Ajirotutu with 24 seconds to play, not only halting San Diego’s losing streak at three games but also keeping flickering playoff hopes alive.

“We’re not fooling ourselves about what we have to do, but we needed this,” said Rivers, whose team is among five at 5-6 and realistically in the hunt for the AFC’s sixth playoff spot. “Before the game, we just said, ‘Let’s put our heads down and work for a full 60 minutes, then look up at the scoreboard and see what happens.’”

For head-swiveling observers, it was more like a tennis match. There were eight lead changes, the most in an NFL game since 2011. The Chiefs, who hadn’t lost at home this season, appeared to have clinched the victory when Alex Smith found Dwayne Bowe with a five-yard touchdown pass with 1 minute 22 seconds remaining at Arrowhead Stadium.

But Rivers and the Chargers weren’t done. They answered with a seven-play, 78-yard drive that took 58 seconds and included a 12-yard catch by Antonio Gates on third and 10, receptions of 19 and 14 yards by Danny Woodhead, and the surgically precise touchdown pass to the double-covered Ajirotutu, who caught the ball as he fell to the ground.

As he came to the line of scrimmage, Rivers alerted Ajirotutu to run a fly pattern if the Chiefs had two deep safeties and would give him an unimpeded release up the sideline. Ajirotutu saw what he needed to see and bolted upfield.

“Philip said, ‘Fly on the boundary,’” said the fourth-year receiver, undrafted from Fresno State, who made his first touchdown catch since 2010. “So I knew that’s a little code word that he usually says that the ball’s coming to you.”

The Chiefs, who had been the NFL’s last undefeated team, dropped to 9-2 after consecutive AFC West losses to Denver and San Diego. It was a big setback to the defense Sunday that they lost the league’s top pass-rushing tandem, Tamba Hali and Justin Houston, to injuries in the second quarter.

Hali suffered a sprained right ankle, and Houston followed with a sprained left elbow. Both will undergo MRI exams Monday.

The Chiefs, who had a league-leading 35 sacks through the first eight games, had failed to get to the quarterback for the better part of the last three games, until safety Eric Berry sacked Rivers late in the fourth quarter. That diminished pass rush applied extra pressure on the secondary, and a defense that hadn’t given up more than 17 points in any home game. It surrendered that many to the Chargers in the fourth quarter.

“I’m not making excuses,” Kansas City Coach Andy Reid said when asked about the injuries to Hali and Houston. “The next guy has to come in, and we expect them to step up and make plays. There’s no excuses.”

There’s no respite for the Chiefs, who Sunday face the Broncos for the second time in three weeks, this time at Arrowhead.

The Chargers don’t have an easy stretch run, either, although four of their final five games are at home. They play host to Cincinnati and the New York Giants before a road game at Denver, and finish with home games against Oakland and Kansas City.

Rivers said Sunday was “kind of what our season’s been about — can you drive and score at the end?

“It’s the kind of win that can save a season.”

On this day, seared into their memories, the Chargers answered that call.

Half-hearted defeats

OK, let’s get this straight. The Indianapolis Colts have played all four NFC West teams. They beat Seattle and San Francisco — two of the NFL’s elite — then, in the last three weeks, are blown out by St. Louis and Arizona?

The Cardinals torched the Colts on Sunday, 40-11, which is one point smaller than the Rams’ margin of victory when they clobbered Indianapolis, 38-8, two weeks ago.

Falling behind early has become a huge problem for the Colts, who have been outscored, 93-12, in the first halves of the last four games.

A dry heat

Arizona has won four in a row, and Sunday’s victory over Indianapolis was a special one for Cardinals Coach Bruce Arians, who last season led the out-of-nowhere Colts to the playoffs as an interim head coach.

But to get where they want to go, the Cardinals have to start winning division games. They have lost their last six NFC West games, and are 0-3 in the division this season. Three of their final four games are against division rivals, with St. Louis and San Francisco at home, and Seattle on the road.

Long day

Brothers Chris and Kyle Long squared off against each other when St. Louis played host to Chicago, and what transpired wasn’t always pretty.

In the second quarter of Chicago’s 42-21 loss, a scuffle broke out in which Kyle Long, a Bears guard, kicked Rams defensive end William Haynes. Chris, also a Rams defensive end, sprinted off the sideline to pull his brother out of the fight.

“It’s tough,” said Chris, the eldest of Hall of Famer Howie Long’s three sons. “One of your best friends [Haynes] and your brother. . . . Yeah, you think about it, but it’s not the first time I’ve restrained him. I think both of those big strong guys probably needed to be restrained there. They’re two of the strongest people I know. I’m just glad everybody got out of there OK. It’s just a heated game.”

Jettisoned

In losing to Baltimore, the New York Jets broke their pattern of win-loss-win-loss-win-loss, which had gone on all season. In the last three games, Jets rookie quarterback Geno Smith has completed eight, eight and nine passes.

Showdown Sunday

The schedule in two weeks features a couple of huge division games, with San Francisco playing host to Seattle and 8-3 Carolina playing at New Orleans.

The 8-3 Panthers have won seven in a row, and quarterback Cam Newton has brought them from behind in the last three. He brought them back Sunday for a 20-16 victory at Miami.

“We didn’t play our best early on; we couldn’t get it going,” said Newton, who ran for 51 yards with a touchdown, and threw the winning touchdown pass to tight end Greg Olsen with 43 seconds left. “But we just find ways to win.”

Steely resolve

Pittsburgh has played its way back into the AFC wild-card conversation after losing its first four games. The Steelers posted a 27-11 victory at Cleveland on Sunday, running their record to 25-5 against the Browns since Cleveland got its team back in 1999.

“When we were 0-4, we knew we couldn’t get four straight wins in one week,” Steelers rookie running back Le’Veon Bell said. “We had to chip away at it. . . . Now we’re 5-6, so we’re just going to keep grinding and grinding.”

Go figure

Some people scoff at statistics, saying number crunchers put too much emphasis on the amount of yards given up or gained.

Well, here’s some ammunition for those skeptics.

Heading into Sunday’s games, Houston boasted the No. 1 defense and No. 8 offense in terms of yards.

The Texans were beaten by Jacksonville, extending their franchise-record losing streak to nine games.

Tied in knots

Minnesota and Green Bay played to a 26-26 deadlock, just the fourth NFL tie since 1998. No doubt Sunday’s outcome generated a simultaneous and spontaneous reaction from thousands of fans trying to keep warm in the Green Bay stands:

The Lambeau Bleep.

sam.farmer@latimes.com

Twitter: @LATimesfarmer