Four teams had a chance to claim post-season places with victories. Only Jacksonville did so, with a win, 20-14 over the Buffalo Bills.
Mark Brunell threw for 317 yards and a touchdown and ran for a score as the Jaguars secured at least a wild card berth in the AFC.
The other three - Tampa Bay, Minnesota and Miami - all went down to defeats, but the Buccaneers were assured of an NFC wild card place when the Super Bowl champions, Green Bay, defeated the Carolina Panthers in a rematch of last year's NFC championship game.
Brett Favre threw for 256 yards and three touchdowns in the 31-10 victory as the Packers eliminated the Panthers from play-off contention with one week remaining in the regular season.
That was good news for the Bucs in the wake of the New York Jets' 31- 0 demolition job on them - the Jets' first win in a December game since 1993.
The often-criticised cornerback Otis Smith returned two interceptions for touchdowns as the Jets - who finished last season 1-15 - regained control of their play-off destiny by joining Miami and New England at the top of the AFC East with 9-6 records.
The rookie Leon Johnson returned a second-half kick-off 101 yards for a TD for the Jets, who had lost their previous two games. Bill Parcells' team can now secure a play-off place by winning at Detroit on Sunday.
"Tampa Bay has seven guys in the Pro Bowl, but they have a young team, we got the jump on them and maybe they had a tough time keeping things in perspective," Parcells said. "They have a young team like us and today was our day."
Cincinnati beat Dallas 31-24, eliminating the Cowboys from play-off contention for the first time since 1990.
Boomer Esiason passed for 242 yards and two touchdowns as the Bengals erupted for 31 unanswered points and Corey Dillon rushed for 129 yards to become the third Cincinnati rookie to reach 1,000 yards in a season.
The Cowboys, who had won the last five NFC East titles, rallied for two touchdowns in the fourth quarter to make things interesting, before losing their fourth game in a row. That is Dallas's longest barren spell since losing their last seven games in 1989.
"We played a pretty good ball game, except for the second and third quarters, when it was disastrous," said the Dallas head coach, Barry Switzer.
Scott Mitchell's one-yard touchdown pass to Herman Moore with three seconds left gave the Detroit Lions hope for a possible play-off place with a 14-13 victory over the reeling Vikings, who have now lost five consecutive games.
Jim Harbaugh threw a career-high four TD passes, including three to tight end Ken Dilger, as the Indianapolis Colts prevented the Miami Dolphins from clinching a play-off place with a 41-0 rout.
"Some days everything just goes wrong and this was just one of those days," said the Miami coach, Jimmy Johnson. "This was just an awful game."
Morten Andersen kicked the 25th game-winning field goal of his career, a 33-yarder as time expired, to give Atlanta their fifth successive win, 20-17 over Philadelphia.
The outcome extinguished the Eagles' play-off dreams, and shortly thereafter Atlanta's own flickering hopes were snuffed out by Detroit's comeback over Minnesota.
The Kansas City Chiefs closed in on home field advantage throughout the AFC play-offs with a 29-7 victory over the San Diego Chargers.
The Baltimore Ravens beat the Tennessee Oilers 21-19 in the last game to be played at 43-year-old Memorial Stadium while Chicago beat St Louis 13-10 in a basement battle.