Unit can't carry Dallas in crunch time

DENVER -- The Dallas Cowboys' defense dominated for more than three quarters Sunday afternoon. The final 10 minutes were a total disaster for a unit forced to play with no margin for error.

Until that point, the Denver Broncos' only scoring drive covered all of 9 yards. But the Broncos had no trouble moving the ball on their last two drives, which was enough to beat a Cowboys team that failed to score points after the first quarter.

Denver had less than 200 total yards before its final two possessions, which covered 138 yards and generated as many points as Dallas had all day.

Broncos receiver Brandon Marshall's 51-yard catch and run, a play in which he leaped over cornerback Terence Newman to make the grab on the sideline and broke several tackles while weaving his way into the end zone with 1:46 remaining, will cause some Cowboys to lose sleep.

"I don't care how good we played for 64 of 65 plays," linebacker Keith Brooking said after the Cowboys' 17-10 loss at Invesco Field. "If there are 65 plays in the game, you have to play well for 65 plays."

Nobody in the Cowboys' locker room was searching for a silver lining after such a frustrating loss, but this defense has made tremendous strides the past two weeks.

Wade Phillips' defense ranked 30th in the league after awful performances against the Tampa Bay Buccaneers (450 total yards) and New York Giants (427 total yards). After those two games, the Cowboys were the only team in the league that hadn't recorded a sack or forced a turnover.

"After the Giants game, we were pretty down on ourselves," said Newman, who thought Marshall should have been flagged on the game-winning play for grabbing Newman's jersey at the line of scrimmage. "We said we needed to come in and make some plays. Then we started playing a little better, getting some trust in there. Guys have been playing their hearts out the last two weeks."

Dallas' defense clicked in the 21-7 Monday night win over the Carolina Panthers, getting three sacks and forcing three turnovers. That performance carried over to Sunday, at least for most of the afternoon.

The Cowboys got pressure on Kyle Orton and recorded three sacks again, matching the total allowed by the Broncos in their first three games. The Cowboys produced a turnover that gave the offense prime field position when Bradie James recovered a fumble forced by DeMarcus Ware on the first snap of the second half. The effort was wasted when Tony Romo threw an interception to end the ensuing drive.

"I guess we didn't make enough plays, but we made a lot of plays," said James, who had eight tackles (two for losses), a sack and the fumble recovery. "I guess we've got to find another way defensively. We've got to find a way to score on defense."

Added defensive end Marcus Spears, who had a sack and tackle for a loss: "It wasn't perfect, but I'm proud of this defense. We've got a lot of guys playing hard, doing whatever it takes to get wins and stop teams from scoring. As long as we continue to have that mentality and mindset, we'll be all right."

All right won't cut it for the Cowboys' defense if Romo can't find his rhythm. Right now, nothing short of outstanding for 60 minutes will do.

Tim MacMahon covers the Dallas cowboys for ESPNDallas.com