LANDOVER, Md. (AP) -- For a little more than a quarter, Robert Griffin III looked like the reigning NFL Offensive Rookie of the Year and the Washington Redskins looked like a legitimate NFL team.
And then, for much of the rest of the game, the Redskins went back to playing the sort of sloppy football that has marked much of head coach Mike Shanahan's tenure.
A defense that gives up yards and points in chunks. An offensive line that does little to protect Griffin. Embarrassing plays on special teams. Mindless penalties.
For the third time in Shanahan's four seasons in charge, Washington will not participate in the postseason.
Letting an early two-TD lead fade away by halftime, and then a three-point edge disappear quickly, too, the Redskins were beaten 24-17 by Eli Manning and the New York Giants on Sunday night.
Washington's fourth consecutive loss dropped its record to 3-9 -- tied for worst in its conference -- and eliminated last season's NFC East champions from playoff contention.
"You don't like to play for pride, but sometimes that's the card that's dealt," Shanahan said, "and that's where we're at right now."
A two-time Super Bowl winner with Denver, he is 24-36 in the regular season under a five-year, $35 million contract.
After the game, Shanahan complained about an odd sequence on Washington's final possession in which the down marker seemed to indicate Washington had a first down, when really it was still only third.
On what wound up being fourth down, Griffin completed a pass to Pierre Garcon, who then was stripped by safety Will Hill, and New York ran out the clock.
Aside from a couple of sideline pratfalls at the end of scampers, Griffin got off to a perfect start, completing his first 12 throws and helping Washington go ahead 14-0 in the second quarter, before the Giants evened the score at halftime.
Under all sorts of scrutiny lately -- involving everything from his father's presence in the locker room to whether offensive linemen are offering a helping hand after plays -- Griffin began 12 for 12 for 111 yards, including a 19-yard touchdown pass to tight end Logan Paulsen.
In the third quarter, Griffin surpassed 3,000 yards passing for the season, making him only the fourth player since the 1970 AFL-NFL merger to throw for that many in each of his first two years. Manning's older brother Peyton, Cam Newton and Andy Dalton were the others.
But the Redskins went away from running back Alfred Morris, giving him only two carries after halftime, and various mistakes seeped into Washington's play by the third quarter. One drive included a holding call on center Will Montgomery, an unsportsmanlike conduct penalty on receiver Santana Moss, and a false start on Nick Barnett on the punt.
Then with the score 14-all in the third quarter, safety Brandon Meriweather picked off Manning and returned it to the New York 12.
But all Washington could muster was a 33-yard field goal by Kai Forbath after Griffin's third-down pass was underthrown and nearly intercepted in the end zone. Intended receiver Garcon kicked the ball, earning a penalty.
"A little frustration," said Griffin, who wound up 24 of 32 for 207 yards. "It's all frustration, because we want to win football games. He knows he can't do that. We've got to keep our composure on the field."
Summed up Garcon: "We have a lot of problems, obviously."
Washington then got the ball back, but managed to set up New York with a short field thanks to a comedy of errors.
Punting from their 38, the Redskins mixed a poor snap by Kyle Nelson -- which gave Sav Rocca no time, and he got off an 18-yard kick -- with a 10-yard holding penalty on Nelson.
"Long story short: Shouldn't have happened," Nelson said.
The Giants got the ball on the Washington 46 and needed only four plays to reach the end zone on Andre Brown's second TD run of the game. That put New York ahead 21-14, and Washington's next drive included two of the day's five sacks of Griffin.
On the drive that ended with the Giants tacking on an insurance field goal, Washington wasted a timeout by challenging a catch that, even Shanahan acknowledged afterward, was clearly a catch.
"Bad decision," the coach said.
Just one among many in a season that could end with a third last-place finish in Shanahan's four seasons.
"I just think we're too good to be a 10-loss football team," Griffin said. "Other people will look at it and say that's what we are and think that guys are going to quit."
Notes: Redskins S Reed Doughty didn't play in the second half after getting a concussion. CB DeAngelo Hall had a left hip injury, and LB London Fletcher limped off with an ankle injury after a fourth-quarter tackle. ... The Redskins allowed New York's Justin Tuck to record a career-high four sacks; he entered the game with 2½ all season.
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