(Reuters) - The Washington Redskins and the Dallas Cowboys both came back from the brink of defeat to win their National Football League games on Sunday and stay in contention for the playoffs as the New York Giants and San Francisco 49ers flexed their muscles.

On a roller-coaster Week 14, full of drama and upsets, the Redskins beat the Baltimore Ravens 31-28 in overtime despite losing star rookie quarterback Robert Griffin III to a knee sprain in the final quarter.

The Cowboys, still mourning the death of linebacker Jerry Brown who was killed in a car crash on Saturday, kicked a field goal as time expired to defeat the Cincinnati Bengals 20-19 in Ohio.

The Giants, last season's Super Bowl champions, romped up their highest score in more than a quarter of a century to hammer the New Orleans Saints 52-27.

The Seattle Seahawks crushed the Arizona Cardinals 58-0, one of the biggest wins in NFL history.

The Atlanta Falcons suffered a shock 30-20 loss, only their second of the season, to the struggling Carolina Panthers, while the Indianapolis Colts inched closer to booking a spot in the postseason with a 27-23 victory over the Tennessee Titans.

The Ravens (9-4) were on the verge of clinching their spot and the AFC North division when they led the Redskins 28-20 with 30 seconds to go and dangerman Griffin out of the game.

But Redskins backup quarterback Kirk Cousins threw an 11-yard touchdown pass to Pierre Garcon, then ran for the two-point conversion to force overtime.

The Redskins said Griffin's injury was not season-ending and the quarterback told reporters he was confident he would be back in action soon.

"I feel the positive vibes coming my way and hopefully everything will be all right," he said.

Kai Forbath sealed Washington's fourth straight win with a 34-yard field goal as the Redskins joined the Cowboys at 7-6.

The Cowboys won for the fourth consecutive time with Dan Bailey booting a 40-yard field goal on the final play of the game after the Cowboys had trailed by nine points at the end of the third quarter.

Dallas head coach Jason Garrett said his players were still in a state of shock after hearing about the death of their team mate.

"I keep using the word 'numb,' but that's how we all feel," he said.

New York rookie David Wilson ran in three touchdowns as the Giants cruised to victory to remain a game ahead of the Redskins and Cowboys in the NFC East.

The Falcons, already assured of their place in the playoffs, trailed 23-0 early in the third quarter against the Panthers, whose second year quarterback, Cam Newton, ran 116 yards and passed for 287.

Atlanta replied with three touchdowns but it was all too late to prevent the Panthers from recording another upset on a day full of comebacks and surprises.

The Colts, once again marshaled by rookie quarterback Andrew Luck, came back from a 13-point deficit to beat the Titans, securing the win with two late field goals from Adam Vinatieri.

The Minnesota Vikings beat the Chicago Bears 21-14 in an all NFC North clash that opened the way for the Green Bay Packers to grab the outright lead in the division if they won Sunday's late feature game against Detroit.

The Pittsburgh Steelers, despite having Ben Roethlisberger back in action, were beaten 34-24 at home by the San Diego Chargers, harming their chance of making the playoffs. Philip Rivers threw three touchdown passes for the Chargers.

The Philadelphia Eagles scored two touchdowns in the last four minutes including one as time expired to beat the Tampa Bay Buccaneers 23-21 and end their eight-game losing streak.

San Francisco quarterback Colin Kaepernick passed for 185 yards and ran for a 50-yard touchdown at Candlestick Park as the 49ers improved to 9-3-1, just ahead of the Seahawks (8-5) in the NFC West.

Marshawn Lynch rushed for 128 yards and three touchdowns as the Seahawks posted the franchise's biggest win and one of the biggest shutouts in the NFL behind Chicago's record 73-0 win over Washington in 1940.