Chargers’ offense rallied to beat the Steelers, but it was the defense that put a stop to Pittsburgh’s dominance

Philip Rivers described the mood in the locker room at halftime of Sunday night’s game at Pittsburgh as “antsy.” The Chargers trailed by 16 points in one of the NFL’s most inhospitable stadiums for visitors, and the Steelers were set to receive the second-half kickoff.

“I don’t think we were down,” Rivers said, “but we knew we had to get going in a hurry.”

The offense did just that, with Rivers leading a dramatic second-half charge that culminated with Michael Badgley’s game-ending 29-yard field goal, but the improbable 33-30 comeback victory would not have been possible without some key defensive stops.

While the offense converted all four third-down plays in the second half, the defense stymied four third-down plays, though Pittsburgh converted a fourth-and-one on its final possession.

After being torched by Steelers wide receiver Antonio Brown, who had six receptions for 117 yards, and committing two costly pass-interference penalties in the first half, the Chargers secondary limited Brown to four more catches for 37 yards and played flag-free football in the second half.

“We had to [avoid] letting one guy beat us,” Chargers coach Anthony Lynn said of Brown. “He had over 100 yards receiving in the first half, so we did some things differently coverage-wise in the second half that slowed him down.

“That opened it up for some other [receivers] to possibly make plays, but we wanted to make sure he wasn’t making those plays.”

Brown burned cornerback Casey Hayward on the Steelers’ first possession with a 46-yard catch on a go route down the left sideline. James Conner’s one-yard touchdown run on the next play gave Pittsburgh a 7-0 lead.

On the Steelers’ next possession, quarterback Ben Roethlisberger lofted a 29-yard pass into the end zone to Ryan Switzer, who was open on a diagonal route. Cornerback Michael Davis, with his back to the ball, ran over Switzer before the ball reached the receiver, an obvious penalty. Conner scored from the one for a 13-0 lead with 4 minutes 41 seconds left in the first quarter.

Another pass-interference call on Davis, who was flagged for riding up the back of JuJu Smith-Schuster on a third-and-four play just before halftime, extended a drive that ended with Roethlisberger’s 28-yard scoring pass to Brown for a 23-7 lead.

As frustrated as the Chargers were, Lynn did not sense any panic at halftime. A Bob Knight-style tantrum was not necessary.

“With this group, you don’t have to throw tables or knock down water coolers to get them going,” Lynn said. “They knew. I could look in their eyes and I could tell these guys were ready to play. I thought the guys were locked in and focused. Coaches were doing a good job coaching guys up and making some changes.”

The biggest adjustment on defense was to double-team Brown. Safety Derwin James often lined up in the box but drifted back and toward Brown’s side just before or right after the snap. That forced Roethlisberger to throw more to Smith-Schuster and his tight ends.

“We were giving them different looks, throwing them a changeup,” said James, who stopped a second-quarter drive deep in Chargers territory with his third interception. “We made the plays when they came to us.”

Desmond King tackled tight end Vance McDonald short of a first down on a third-down play, forcing a punt on Pittsburgh’s first possession of the second half.

Rivers drove the Chargers 88 yards on 13 plays, connecting with Keenan Allen on a 10-yard scoring pass and Antonio Gates on a two-point conversion to cut the deficit to 23-15.

The Chargers did not sack or hit Roethlisberger in the first three quarters. That changed early in the fourth quarter when Joey Bosa dropped the Steelers quarterback for a 10-yard loss. Two plays later, King returned a punt 73 yards for a touchdown and Allen caught a two-point conversion pass for a 23-23 tie.

Pass breakups by King and Adrian Phillips on second and third down forced another punt, after which the Chargers drove 79 yards on seven plays for the go-ahead score.

“We’ve been in some close games, and when you win them, it’s reassuring,” Rivers said. “It doesn’t mean you’re going to win them every time, but if we find ourselves in a 23-7 hole, we’re going to say, ‘Hey, we were down like this in Pittsburgh.’ It doesn’t mean it’s going to happen again, but we’ll dang sure know we can do it.”

Etc.

Rivers’ 26^th fourth-quarter comeback marked the seventh time he has orchestrated a win after trailing by 16 or more points, tying Peyton Manning for the most in NFL history. … The Chargers rank third in the NFL with 54 runs of 10 or more yards, and each of their rushers with 20 or more carries — Melvin Gordon, Austin Ekeler and Justin Jackson — is averaging more than five yards per carry. … Cycling was the theme of Tuesday’s off day. Several Chargers, including Badgley and Davis, surprised 166 students who took part in an essay competition from Cesar Chavez Elementary School in Long Beach with new bikes, and running back Melvin Gordon helped 100 children from Gardena’s Falcons Youth and Family Services decorate new bicycles at StubHub Center.

mike.digiovanna@latimes.com

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