The Bills trailed 10-0. They lead 14-10 at halftime.
Buffalo woke up midway through the second quarter, getting out of its own way to score back-to-back touchdowns.
The Bills had 15 plays for only 56 yards on their first three possessions, with all three ending in punts. They had a one-play, 57-yard score on a pass from Josh Allen to Gabe Davis on their fourth possession.
The Bills then closed out the half with an eight-play, 63-yard drive, with Allen scoring on a 2-yard touchdown run. Allen scored with 38 seconds remaining in the half.
The Bills have outgained the Chargers 186 to 150.
Allen has completed 7 of 11 passes for 124 yards, with Davis catching three for 94. Stefon Diggs injured his neck early in the game, missed two plays and returned but has since spent time on the sideline. He has one catch for no yards.
James Cook has eight carries for 37 yards and Leonard Fournette, in his 2023 debut, has three carries for 17 yards.
Easton Stick has completed 10 of 14 passes for 101 yards. Gerald Everett has four catches for 26 yards, and Austin Ekeler has nine carries for 47 yards.