Rivers set the record on a 12-yard pass to tight end Hunter Henry early in the second quarter. After the completion, Rivers was 11 of 13 for 131 yards and a touchdown on the game with the Chargers leading, 7-0. Rivers had 43,047 career passing yards upon breaking the mark.
Rivers finished the game completing 18 of 29 passes for 178 yards and a touchdown.
"Philip is the best in the business," Chargers coach Mike McCoy said. "He's been that way for a long time ... He's a special player."
It wasn't the first time Rivers set a team record. The five-time Pro Bowler already holds team records for quarterback wins (93), passing completions (3,579) and passing touchdowns (292).
Before the game, Rivers, 34, said passing Fouts wouldn't be lost on him.
"I'm not going to lie, it means a lot," Rivers told ESPN. "When you're 25 or 26 you say, 'I'll look back one day and appreciate it.' Now you say 'what in the world? How did this happen?'"