Barber is calling it quits after 10 NFL seasons with the Giants

The running back, who retires after this season, had 23 carries and scored on runs of 15, 55 and 50 yards, setting a new club single-game yardage record.

But the Giants (8-8) almost squandered a 20-point lead as the Redskins (5-11) mounted a late comeback.

However, Barber's haul saw them through and they now wait on Sunday's results.

The stuttering Giants had lost six of their previous seven games, and Barber admitted: "We had to win to keep playing.

"There are certain things that motivate you, push you. It's partly because of the circumstances of this game, my last (regular season) one."

Barber passed the 1,500-yard mark in rushing for the third consecutive season and now has 1,662 yards.

He also caught three passes for 24 yards, the only New York receiver to catch more than two passes.

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New York had to overcome another mediocre effort from quarterback Eli Manning before virtually assuring themselves a berth in the NFC play-offs, barring a highly improbable series of results.

Green Bay would need a big victory over Chicago on Sunday and several other results to go their way for the Packers to supplant the Giants for the final spot.

Manning was just 12-for-26 for 101 yards, throwing a six-yard touchdown to Tim Carter for the other New York score. Jay Feely kicked 31 and 34-yard field goals.

New York led 27-7 in the third quarter but two TDs brought Washington to within six points before Barber's five-yard TD with 6:13 remaining secured the win.