The Chargers took full advantage in Sunday's wild-card encounter as Bengals quarterback Andy Dalton suffered a nightmare outing, coughing up two interceptions and a fumble in a scoreless second half for the hosts.
Dalton rushed for Cincinnati's only touchdown of the contest but his subsequent woes helped the Chargers outscore the Bengals 20-0 after the interval on their way to a fifth straight victory.
San Diego quarterback Philip Rivers was happy to rely on the running game as completed 12 of 16 for 128 yards, with a lone touchdown pass going to Ladarius Green.
Danny Woodhead opened the scoring with a five-yard run in the first quarter, while Ronnie Brown ran in a 58-yard touchdown to set the seal on the win, as the AFC North-winning Bengals fell at the first hurdle in the play-offs for the third year in a row.
Shayne Graham's field goal on the final play of the game gave the New Orleans Saints a 26-24 win over the Philadelphia Eagles.
It was Graham's third field goal of the game for the the Saints, for whom Drew Brees had one touchdown pass and Mark Ingram rushed for a score.
They will next face the Seattle Seahawks.