It was the Chargers’ first major opportunity to reintroduce themselves. On fourth and one in the season opener, however, it wasn’t Joey Bosa or Khalil Mack who made the play that sent the defense’s first warning shot of the Jim Harbaugh era.

It was Poona Ford and Otito Ogbonnia who came crashing into the backfield.

The pair of 300-pound tackles who combined to stop the Las Vegas Raiders on the Chargers’ second defensive series of the season have turned the team’s line from a question mark to a strength while setting the tone for the stingiest scoring defense in the NFL, giving up just 6.5 points per game.

The Chargers’ established edge rushers are the stars of the defensive front, and the interior linemen are ready to make names for themselves as well.

Morgan Fox is the vocal leader among the Chargers’ defensive tackles.

(Kyusung Gong / Associated Press)

“People aren’t talking about us, people might think we’re not this, but we know who we are as players,” defensive lineman Morgan Fox said. “Nothing matters to us besides the people in our room, and at the end of the day, we just want to prove ourselves right.”

The Chargers (2-0) also have given up only one red zone drive, the fewest in the NFL. They smothered the Raiders in their divisional rival’s first game under a new offensive coordinator and dominated the struggling Carolina Panthers, who benched second-year quarterback Bryce Young one day later.

The Chargers have a new challenge, however, in the Pittsburgh Steelers. The matchup Sunday of unbeaten teams is an official “playoff opener,” Harbaugh said, as it will be their first game against a team that went to the playoffs last season.

The Steelers are 2-0 on the road to begin a season for the first time since 1999, and Justin Fields, who has been starting at quarterback for injured Russell Wilson, is expected to reprise the role Sunday at Pittsburgh’s Acrisure Stadium.

Already off to their best start since 2012, the Chargers could go 3-0 for the first time since 2002.

The Chargers are beginning a turnaround after ranking 24th in points given up last season. It started with defensive coordinator Jesse Minter, who is in his first year as an NFL play-caller after two years coordinating the defense at Michigan. The 41-year-old is simply “really good at what he does,” said Harbaugh, who coached with Minter at Michigan for two seasons.

General manager Joe Hortiz retooled the roster with underrated acquisitions, including signing Ford to a one-year contract after the seven-year veteran had a disappointing season with Buffalo.

The 5-foot-11, 310-pound defensive tackle joined the Bills as a high-profile signing hoping to contend for a Super Bowl. He had established himself as a consistent force over five seasons in Seattle, but had a career-low nine tackles for Buffalo and was a healthy scratch on the inactive list nine of 17 times.

Back on the West Coast in the opener, Ford didn’t waste any time reminding the league of his potential with three tackles, including one for loss, and an interception off a tipped pass against the Raiders.

“These guys are really hungry to prove that they’re capable, really good NFL players,” Minter said, also referencing cornerback Kristian Fulton, who was coming off a nagging hamstring injury in Tennessee.

The 28-year-old Ford is a veteran in a defensive line that has only three players with more than three seasons of experience. However, Ford told reporters during the preseason that he leaves much of the vocal leadership and media duties of the defensive line group to the 30-year-old Fox, who is in his third year with the Chargers after stints with the Rams and the Panthers.

Ford prefers to let his play speak for itself.

Defensive tackle Otito Ogbonnia (93) has been impressive during the Chargers’ two victories.

(Kyusung Gong / Associated Press)

“This guy is a beast,” Ogbonnia said, standing one locker away from Ford’s at the practice facility.

Ogbonnia, 22, marveled at Ford’s unshakable technique that is always the same no matter the play. Ogbonnia has tried to adopt the same consistency while making a significant jump in his third season.

The UCLA alumnus suffered a ruptured patellar tendon halfway through his rookie season. He returned to play eight games last season with two starts, and the fifth-round pick solidified a starting role next to Ford and Fox.

Harbaugh said he “can’t think of anybody that’s been as improved and as dynamic as Otito.”

“He really took a leap forward in just being consistent to the little details,” said Fox, who has four tackles and a half-sack in two games. “Being consistent with his pad level, being consistent with his hands. He’s really taken a stride in that way because you see when he does it, he’s a very strong, very disruptive player.”

Feeling the healthiest he’s been as a pro, Ogbonnia has emphasized the “overall violence” of his game. Even when his technique isn’t perfect, he wants his movements to show the strength he hopes will define the defense.

Ogbonnia wasn’t afraid to show that mindset when a Raiders offensive lineman tried to pull the defensive tackle off the pile in the first game. Ogbonnia went face mask to face mask against his opponent until teammates pulled him back.

It didn’t matter he was up against fellow former UCLA Bruin Kolton Miller.