But on the first play, Fields’ pass to Cordarrelle Patterson was knocked into the air, where it was intercepted by former Steelers outside linebacker Bud Dupree at the 34-yard line, marking the first turnover of the game.

Elandon Roberts sacked Herbert on the first attempt to push the Chargers back, and after a three-and-out, the Steelers got the ball back at their own 15-yard line.

Aided by three penalties from Los Angeles – including personal fouls on safety Derwin James and Khalil Mack – the Steelers marched down the field and scored a 27-yard field goal by Boswell that gave them a 13-10 lead with 14:14 minutes left in the game.

“(We) played great for a long time. Played great on offense for a long time. Played great on defense for a long time,” Chargers head coach Jim Harbaugh said. “And then the drive with the three penalties, even on that drive they were able to hold on to a field goal, 45-yard penalty.”

Herbert and left tackle Rashawn Slater were both injured on the previous drive. Herbert aggravated an ankle injury that had kept him out of practice all week, and Slater suffered a pectoral muscle injury, forcing backup Taylor Heinicke to play for Los Angeles.

The Chargers took the ball to the halfway line, but TJ Watt made a sack on third down, ending the danger and forcing Los Angeles to punt.

The Steelers took over inside their own 20 and moved the ball to midfield when Fields found Austin in the middle of the field, alone in the Chargers’ zone defense. Austin caught the ball, turned forward and outran safety Elijah Molden to the end zone, giving the Steelers a 20-10 lead with 7:02 to play.

“They were just in the zone. Quartering is really just a high-low play with the hook defender,” Fields said. “The hook defender took (Pickens) under him and Calvin was right behind him. Great play.”

Herbig and Cam Heyward both recorded sacks on Los Angeles’ next possession, ending any chance the Chargers had of a comeback.

The Steelers offense nullified that point and ran down the clock for the rest of the game. Najee Harris finished things off with a run to the 1 at the two-minute warning.

The Steelers rushed for 114 yards, with Harris finishing with 70 yards on 18 attempts despite a slow start.

“They just wanted to be the best defense on the field,” Tomlin said of his defense, which went into the game having allowed the second-fewest points (16) this season behind Los Angeles (13).

“They react to these things and take these challenges very personally, and they played accordingly.”