What began as a day of capitalization and sharp execution finished with the wheels falling off the wagon.

Until early in the third quarter, nearly everything went as well as New England could have hoped. The offense was sustaining drives and the defense was causing turnovers. Denver was doing everything it could to help the Patriots put points on the board. Despite holding two 10-point leads, New England returned the mental breakdowns and poor play to allow the Broncos to escape with a 31-20 victory.

It was a very winnable game, one that could have given the Patriots a winning record for the first time since 1999. A victory would have elevated expectations for the remainder of the season, but for now the Patriots have to accept that showing improvement in a tough environment is not enough to finish the job.

New England held the upper hand for much of the game, but it proved once again that this is not a team that can afford to make mistakes or give away golden opportunities.

"Denver played well and deserved to win," Head Coach Bill Belichick said. "They are a good football team, but I think we know we can beat them. But we didn't beat them today."

New England looked to have very good odds of doing just that in the first half. Everything seemed to come out in the Patriots favor. The Broncos were flagged for three 15-yard personal foul penalties in the first half. The Patriots, meanwhile, were awarded three third down conversions because of penalties. All three possessions resulted in New England points.

For the third week in a row, quarterback Tom Brady was making the game look easy, making every throw he needed to. 

On the other side of the ball, the defense started strong as well. The Patriots opened with a three-and-out when Ty Law came up with a huge stop of Rod Smith (6 catches, 159 yards, one touchdown) and limited him to a 2-yard reception on third-and-three, forcing a punt. New England scored a touchdown on the ensuing drive, and because the Patriots jumped out to a quick lead with 10 points in two possessions, the Broncos could not work their running game very much in the first half (15 carries, 51 yards).

Late in the half, Tedy Bruschi picked off a Brian Griese pass deflected by safety Matt Stevens. Even when Bruschi fumbled on the return, Stevens came up with the recovery, and Griese was tagged for a 15-yard personal foul. Once again everything worked out well, as New England needed just three plays to get the ball in the end zone on a 5-yard pass to Troy Brown.

"Going into halftime we were up 17-10 and we came out and got the ball back," Brady said. "We really played our game in the first half. I wouldn't say we got taken out of our game in the second half, but we just made too many mistakes."

As bright as Brady shined through three quarters (21-of-24, 163 yards, 2 touchdowns) the luster faded quickly with four fourth quarter interceptions. The entire offense had several bouts of miscommunication and mental lapses that caused the Patriots to burn all three of its timeouts when there was still 13:12 left in the game.

"We got outplayed in the second half," said wide receiver David Patten, who finished with five catches for 62 yards and a touchdown. "I'm not sure I have an answer right now, but the offense was not working as well in the second half, and we had communication problems. They made more plays than we did, and the better team won today."

The second half problems were not exclusive to the offense. With New England leading 17-10 in the third quarter, a major mental gaffe handed Denver a big play. Griese hit tight end Desmond Clark for a 35-yard pass play that should have been limited to about 7 yards. On the catch Clark fell near the sideline, and Stevens jumped over him, but never downed him. Clark got up and ran to the Patriots 40 before being forced out of bounds.

"I thought he was out of bounds," Stevens said. "I made a mistake and there isn't a good reason."

Less than three minutes later, the Broncos got their second unanswered touchdown on a 6-yard pass to Dwayne Carswell that gave them the lead for the first time.

From there, it was up to Brady to try and find some more magic. The Patriots embarked on a 54-yard drive and again were the recipients of a bad Denver penalty. On a third-and-three at the Denver 22, Trevor Pryce was flagged for roughing the passer, giving New England a first down at the 11.

That's where the magic ran out. After an incompletion, a 3-yard run by Kevin Faulk and a false start on Damien Woody, Brady faced third-and-12 at the 13. He went for broke and tried to get Patten in the back of the end zone, but threw across the field while moving to his right, which prevented him from getting any zip on the ball. The pass was picked off by Denard Walker. It was the first career interception for Brady in 163 attempts.

"Tom went out of the pocket and caught me open at the last second," Patten said. "The defensive back slipped on the play, but he came back and made a great play."

Trying to rally the offense, Brady was picked three times in his next nine attempts, including one for a 39-yard touchdown return by Walker. 

"You don't want to throw interceptions, especially in the second half," Brady said. "You have to learn to take advantage of the opportunities you have and make every throw when it is there."

Despite the loss, Belichick saw things he liked. His team moved the ball on offense and continued to improve in the running game (24 carries, 117 yards). Denver was held to just 86 rushing yards, and the defense forced two turnovers that resulted in 10 points. While the end results were not desirable, the signs of being a competitive team were there.

"I thought we lost to a good football team out there today," Belichick said. "We had our chances. It was a 24-20 game in the fourth quarter and we needed a good drive to get it in the end zone.

"They had some players step up and make some big plays. We did too, just not as many. We made too many errors in the second half, and we couldn't come back to win it."

So close to being on the winning side, both with the game and their overall record, the Patriots were understandably stung by the loss. 

"Every week there is pressure on us to produce," Patten said. "It hurts when things don't go right, but we showed that we are getting better. Both sides of the ball made plays; we just need to execute more consistently. We feel like we're getting there."

With another road game waiting in Atlanta next week, they know things won't get easier, but they do have confidence that they can compete every time out — as long as they execute and capitalize on their opportunities.