Updated

ARLINGTON, Texas -- Tony Romo's season might be over, and the Dallas Cowboys' season might as well be.

As for Eli Manning and the New York Giants, everything's clicking.

Romo broke his left collarbone in the second quarter, then his teammates let a 13-point lead turn into a 41-35 loss Monday night that helps send both teams in opposite directions in the NFC East.

The Giants (5-2) won their fourth straight and moved a full game ahead in the division.

Dallas slumped to 1-5, its worst start since 1989. That was the year Jerry Jones bought the team, Jimmy Johnson took over as coach and the Cowboys went 1-15. Everyone knew that team would stink. This club, however, had Super Bowl hopes.

Any chance of turning this season around ended when Romo was drilled by blitzing linebacker Michael Boley in the second quarter. Recovery time is generally 8 to 10 weeks and, by then, there may not be any reason to rush back.

Romo went down hard on his left shoulder and remained flat on his back. X-rays showed the break before halftime, but he was back on the sideline for the second half, his arm in a sling and covered by a jacket. He wore a headset and trying to encourage teammates, but there wasn't much to cheer about.

The Cowboys actually were up only 10-7 when Romo left and stretched it to 20-7. Then New York scored on its next five possessions, a 31-point flurry that sent home much of the crowd by the middle of the third quarter. The Giants actually were ahead by the time Romo's injury was diagnosed.

Dallas backup Jon Kitna hadn't played since Oct. 5, 2008, when he was part of Detroit's winless season. Whether it was the long layoff, being 38 or both, he sure looked rusty.

His first and third passes were tipped. The next time he dropped back, he was sacked for a 10-yard loss, forcing Dallas to punt from its own end zone. The Giants took advantage of the short field to score the go-ahead touchdown. His next pass was fumbled by Jason Witten, setting up Tynes' long field goal. It got so bad that there was a mock cheer when he completed a pass for a first down early in fourth quarter.

Kitna ended up throwing a pair of touchdown passes to rookie Dez Bryant in the final 3;17, but Dallas failed to recover onside kicks after each. New York got another field goal from Tynes after the first, then ran out the clock after the second.

With the Super Bowl coming to Cowboys Stadium, and his club coming off a division title and a playoff victory, Cowboys owner Jerry Jones knew he was headed toward a season he'd never forget. Now, he wishes he could -- and he still has 10 games left.

The craziest part about this game was how many things the Cowboys did right: A club that had only four takeaways all season snatched five. A special teams group that was getting known for giving up big plays made a huge one -- a 93-yard punt return for a touchdown by Bryant. They drew only five penalties.

But they also went 0 for 10 on third downs. And Romo wasn't the only guy lost to injury. Defensive end Jason Hatcher and left guard Montrae Holland hurt groins. Holland already was filling in for injured starter Kyle Kosier, so the Cowboys had to go with Phil Costa, a rookie free agent who was making his NFL debut.

Romo had thrown every pass by a Cowboys quarterback since Nov. 16, 2008, when he returned from a broken pinkie on his throwing hand that cost him three games. Those were the only games he'd missed since replacing Drew Bledsoe as Dallas' quarterback in October 2006.

He set the franchise record for yards passing in a season last year, making the Pro Bowl for the third time. In his brief action Monday night, he broke his own club record by throwing for a touchdown in his 18th straight game. He was 5 of 7 for 39 yards.

Kitna was 16 of 33 for 187 yards.

Manning was 25 of 35 for 306 yards. This was the fourth time he'd thrown four TD passes.

Hakeem Nicks caught nine passes for 108 yards and two touchdowns. Steve Smith caught nine passes for 101 yards and a touchdown. Mario Manningham had the other TD catch.

Ahmad Bradshaw ran 24 times for 126 yards. Jacobs had 75 yards on 12 carries.

The Cowboys pulled out the stops this week to try turning things around. Team owner Jerry Jones gave an encouraging speech Monday, officials worked practices on Wednesday and Thursday and Hall of Famers Bob Lilly and Tony Dorsett were honorary captains for this game. (Hours earlier, Dorsett called the team "a bunch of underachievers.") They drummed up some loud applause by showing clips of the World Series-bound Texas Rangers, then cutting to Nolan Ryan in the stands.

Apparently, the Giants are making up for what the Yankees failed to do on their trip to Arlington last weekend.