Foxborough, Mass. - The New England Patriots' quick start is over and the once-rosy outlook significantly dimmer just three weeks into the season.

After blowing a 21-point lead in a loss to Buffalo on Sunday, the Pats find themselves trying to avoid a .500 start instead of making a big run through the early part of their schedule.

New England was still a little stunned Monday. The Patriots often jump out to big leads, but rarely let them slip away - especially against the Bills. And Tom Brady regularly throws for hundreds of yards and multiple touchdowns, not interceptions.

Brady matched his career worst with four picks on Sunday and the defense couldn't hold the big lead, allowing the Bills 448 yards of offense as Buffalo rallied and won 34-31 on a last-second field goal. The winning kick was set up by a 38-yard pass on one of several defensive breakdowns by New England.

"The game came down to us on the defensive side of the ball and we just didn't make the plays that were needed to win the game," linebacker Jerod Mayo said Monday. "Plays were being made on both sides of the ball. Buffalo just made more."

So instead of playing for a 4-0 start, the Patriots will be trying to avoid opening the season 2-2 when they visit Oakland on Sunday. The surprising Raiders are also 2-1 and could really set back the Patriots before they return home for their first showdown of the season against the rival New York Jets on Oct. 9.

The loss overshadowed a record start for Brady, whose 1,327 yards passing are the most in any three-week span in NFL history. Brady surpassed the 1,257 yards Drew Brees compiled in 2006 and already has 11 touchdowns with five interceptions, four of which came Sunday in the debacle at Buffalo.

"It's like a boxing match. We're going to get hit, and they're going to get hit, and hopefully at the end you connect more times than they do. I thought we had our opportunities," Brady said Monday during his weekly appearance on WEEI radio. "I don't think we come out of the game ... thinking that we're a bad football team. It's just, if we play the way that we played, we're not going to be very good."

Brady also threw for four touchdowns on Sunday, including two on New England's first two possessions. The Patriots added another on a 26-yard pass from Brady to Rob Gronkowski with 6:01 left in the second quarter for a 21-0 lead.

But Buffalo cut the margin to 21-10 by halftime, then outplayed New England in the second half. The Patriots needed a 6-yard touchdown pass from Brady to Wes Welker with 3:25 left - on fourth down - to tie it at 31.

Then the resilient Bills broke through the New England defense again.

Ryan Fitzpatrick found Fred Jackson on a short pass over the middle and Jackson broke it all the way to the goal line with 1:48 remaining. The play was called a touchdown, reviewed and overturned after officials ruled that Devin McCourty pulled down Jackson at the 1-yard line.

Had McCourty let Jackson cross into the end zone, Brady and the Patriots would have had plenty of time to engineer another drive and possibly force overtime. Instead, Buffalo was able to run down the clock and end a 15-game losing streak to the Patriots on Rian Lindell's 28-yard field goal as time expired.

So now both the Patriots and Jets trail the Bills in the AFC East.

Coach Bill Belichick said McCourty acted on instinct and wouldn't fault a defensive player for tackling an opponent on his way to the end zone.

After all, there were plenty of other blunders Belichick and his staff can focus on when the Patriots return to practice Wednesday.

"They did a better of job executing some plays than we did defending them," Belichick said. "We made some plays. They made some. In the end they made more than we did. We've just got to do a better job of coaching and playing."