Quarterback Mark Herrmann, filling in for the injured Dan Fouts, fired a 23-yard pass to Charlie Joiner for the go-ahead touchdown today to lead the San Diego Chargers to a 20-14 National Football League victory over the Philadelphia Eagles.

San Diego improved to 8-7 and Philadelphia fell to 6-9. Both teams are out of playoff contention.

Cornerback Danny Walters stopped the Eagles' final drive with his second interception of Ron Jaworski with 3:09 left in the game.

Fouts left the game with a bruised left knee after taking a hit following a 46-yard pass completion to Wes Chandler that put the ball on the Eagles' 11-yard line with about three minutes gone in the third period. Two plays later, Tim Spencer bulled his way into the end zone from six yards out for the Chargers' first touchdown of the day.

The Eagles came back to take a 14-10 lead when tight end Dave Little recovered teammate Major Everett's fumble in the end zone. Everett had fumbled at the San Diego one after catching a seven-yard pass.

San Diego took the lead for good at 17-14 when Herrmann capped a seven-play, 74-yard drive with his pass to Joiner midway through the third period. Bob Thomas' second field goal, a 46-yarder with 5:16 remaining, completed the San Diego scoring.

The Eagles held a 7-3 lead after a messy first half in which the teams combined for five turnovers.

San Diego's Lionel James broke Lenny Moore's NFL season record of 938 receiving yards by a running back.