---

FOXBORO — Defense not only wins ballgames, it can cover up a multitude of sins once it’s played properly.

So it was that in the game that propelled the Patriots to the .500 level for their entire existence, their defense made the big plays down the stretch that made a lot of people forget about some less-than-sterling moments earlier in the contest.

Bill Belichick never forgets, however.

"We tackled a little bit better from about the middle of the second quarter," Belichick said after the Patriots’ 19-17 win over the Buffalo Bills in the season opener at Gillette Stadium. "But we missed a lot of tackles. We had some second-and-long situations they got out of there — snapped the ball over the quarterback’s head, hit a long pass, ran a screen down behind the line of scrimmage, made a long run, and stuff like that.

"Our guys tried to stay aggressive, and I thought we did play better as the game went along," he said. "But we gave up too many plays early in the game." Compare the first half and the second half, however, and there’s a world of difference. The Bills had all but 74 of their 240 total yards in the first half because the Patriots made the proper adjustments at the break — not to mention two plays that turned the course of the game in their favor.

Don Davis’ fourth-and-1 tackle of Willis McGahee at the New England 7 early in the fourth quarter turned the momentum in the Patriots’ favor, and Ty Warren’s safety-causing sack of J.P. Losman in the end zone with 8:33 left to play provided the winning points for the defending divisional champions.

"It was adjustments," Patriots’ nose tackle Vince Wilfork said. "In the first half we went out there and were doing some stuff that we shouldn’t have been doing, and on top of that, seeing some stuff that we hadn’t prepared for. So we just had to make it to the second half and make our adjustments on the sideline."

Warren, in his fourth NFL season out of Texas A&M, got a rare opportunity to post a safety — something the Patriots haven’t done since 2003 — and to have it win the game.

A penalty on a kickoff had backed the Bills up to their own 9, and after an incomplete pass by Losman, Warren teamed with Junior Seau to drop McGahee for a loss of a yard.

On the third-and-11 play, Losman dropped back and was quickly pressured by linebacker Tully Banta-Cain. He tried to run away from the pressure, but Warren was there to pull him down and make sure that he came down inside the end zone.

"It was just a defensive play that was played well by the whole defense," Warren said. "The secondary held their end down back there, which forced Losman to hold the ball as long as he did. And that allowed me to get back there and put pressure on him.

"It was just read and react to the play," the 6-5, 300-pound defensive tackle said.

Officials are usually reluctant to ring up a safety in the pros, preferring to give the trapped player forward progress if it’s close. But there was no mistaking where Warren brought Losman down.

"I saw him go into the end zone and I was trying to get to him before he got out," Warren said. "When you get to put points on the board defensively, it’s a plus." "Safeties are something that don’t come too often," added linebacker Rosevelt Colvin, who contributed a 9-yard sack of Losman earlier in the game. "I think I’ve probably been part of one safety in my entire football career. It’s good because you produce points, and then you get the ball back.

"It turned out to be the difference in the game ... it’s a huge play," he said. "We’d been running some different pressures the whole game, Ty came free, and that’s what this defense is all about. When you get your opportunity to make a play, make it, so the other 10 guys know that you know what you’re there for."