ARLINGTON, Texas -- This was a collapse.

The Cowboys blew a 12-point fourth-quarter lead and their first-place standing in the NFC East on Sunday night in one of the worst losses of the season.

Yes, worse than last week in Arizona. Worse than the 24-3 lead that was lost to Detroit. Worse than that fourth-quarter meltdown vs. Tom Brady in New England.

The New York Giants rallied to beat the Dallas Cowboys 37-34 at Cowboys Stadium.

What it means?: The Cowboys are tied for first place in the NFC East with the Giants. The Cowboys had a chance to forge a two-game lead in the division and failed to do it. Now with three games remaining, a potential playoff berth is slipping away.

The blocked kick: Dan Bailey had a potential game-tying field goal blocked from 47 yards in the closing seconds. It was the first blocked kick of the season against the Cowboys and first miss at home by Bailey. He made the first attempt but the New York Giants had called timeout before the snap, forcing another kick.

Austin comes up big: On the final possession, wide receiver Miles Austin made catches of 23 and 22 yards to set up Bailey's field goal try. Austin was quiet most of the night but came through when necessary.

More fourth-quarter penalties: The Cowboys were penalized three times in the fourth quarter and now have 35 on the season in the fourth, which puts them in the Top 5 in the NFL.

Injuries bother Cowboys:The Cowboys lost starting running back DeMarco Murray possibly for the season with a fractured right ankle and a high ankle sprain. Felix Jones was the lone running back on the game-day roster with Murray out. Phillip Tanner is on injured reserve with a hamstring injury and the team has one player on the practice squad, Chauncey Washington, who could get called up. Mike Jenkins (shoulder), Barry Church (shoulder), Jay Ratliff (back), Sean Lee (hand) and Phil Costa (concussion) all left the game but returned. Jones finished with 16 carries for 106 yards.

Lee with big play: The top three defensive players on the Cowboys in 2011 have been DeMarcus Ware, Ratliff and Sean Lee. It was the second-year inside linebacker making another big play in the fourth quarter. Eli Manning threw a side-armed pass that was tipped by Victor Butler. And Lee, blocked by tackle David Diehl, was able to snag the ball out of the air and return it 30 yards. It was Lee's first interception since Oct. 16 at New England and the fourth of the season.

Giants' Bradshaw benched: Giants starting running back Ahmad Bradshaw was benched for the first half for violation of team rules. He did get the first three snaps of the second half and didn't have much of an impact. On a third-and-2 from the New York 41, Bradshaw was shut down by Ratliff for a 3-yard loss.

Another 100-yard receiver: For the fourth consecutive week, the Cowboys allowed a wide receiver to get 100 yards. This week it was Hakeem Nicks, who finished with seven catches for 154 yards.

What's next?: A trip to Tampa Bay and another game with playoff implications. The Cowboys need to keep pace with the Giants. If not, their season could be lost.