The Steelers tied the game at 7-7 on a 5-yard Justin Fields touchdown run before allowing a field goal at the end of the half as the Chargers took a 10-7 lead.
The Steelers nearly answered at the end of the half, as Field connected with George Pickens on a 27-yard pass to midfield before Chris Boswell was sent out to attempt a 62-yard field goal as time expired.
Boswell missed the attempt – one of just three misses he had all season – as the Chargers took a 10-7 to the half.
The Steelers tied the game at 10-10 on the opening possession of the second half on a Boswell field goal, and Herbig sacked Herbert on the Chargers’ second play on the ensuing possession, aggravating an ankle injury he entered the game nursing.
Former Steelers linebacker Bud Dupree intercepted Fields on a tipped pass at the Los Angeles 41. But Elandon Roberts sacked Herbert on first down and Herbert handed the ball off to JK Dobbins twice before exiting the game following another Chargers punt.
The Steelers added another Boswell field goal early in the fourth quarter, and Fields tossed a 55-yard touchdown to Calvin Austin III on their next possession to put the Steelers ahead, 20-10.
The Steelers defense, meanwhile, clamped down on the Chargers, allowing minus-5 offensive yards in the second half, as they sacked Herbert and backup Taylor Heinicke five times, including two by Herbig. Los Angeles finished the game with just 166 yards of offense.
Fields completed 25-of-32 passes for 245 yards with a touchdown and interception while also rushing for a score. Najee Harris had 18 carries for 70 yards, while Austin had four receptions for 95 yards and a touchdown.
Patrick Queen had a team-high eight tackles.
The 20 points allowed by the Chargers matched their season-high in a road game in 2024.