FOXBOROUGH, Mass. — The New England Patriots may not go undefeated in the regular season. But it won’t be because they beat themselves.

They let other teams do that.

The Patriots improved to 10-0 Monday night, defeating the Buffalo Bills 20-13 at Gillette Stadium. It’s the second time in franchise history the Patriots have been 10-0, the other coming in 2007 when they completed a 16-0 regular season.

The game was no masterpiece. Both teams struggled. Even the officials had trouble with some calls, much to the anger of the fans.

But the game also displayed why the Patriots will win the AFC East for the seventh consecutive year. They don’t beat themselves, unlike the Bills.

In a game in which the Patriots lost another two wide receivers – Aaron Dobson left in the second quarter with an ankle injury that didn’t look good; Danny Amendola left in the third with a knee injury – and further depleted their offensive capabilities, Buffalo missed an opportunity to make a statement because the Bills made too many mistakes.

Yes, the Patriots make mistakes.

They miss blocks.

Tom Brady throws interceptions.

They miss tackles.

They commit penalties.

But in crucial moments, they step up and make a play.

The Bills couldn’t Monday night.

And it started early.

On New England’s first drive, Bacarri Rambo appeared to intercept a pass that tipped off Rob Gronkowski. But off-setting penalties, including a defensive holding on Buffalo’s Corey Graham, wiped it out.

Four plays later, a pass interference call on Buffalo’s Stephon Gilmore kept the drive going. It ended with Stephen Gostkowski kicking a 35-yard field goal, giving the Patriots a 3-0 lead.

Fast forward to late in the second quarter. Buffalo’s Dan Carpenter attempted a 48-yard field goal that would have given Buffalo the lead. But he hit the right upright.

New England took over, Brady led the Patriots to a touchdown on a 20-yard pass to James White, who eluded Graham at the 20, and it was 10-3 at the half.

Then in the third quarter, with New England leading 17-10, the Bills forced a punt. Leodis McKelvin fielded it, but was hit from behind by New England’s Brandon King (who? Exactly.) McKelvin fumbled. The Patriots’ Jonathan Freeny scooped it up. Although he fumbled, the ball rolled out of bounds and New England kept the ball.

Gostkowski kicked another field goal and it was 20-10.

McKelvin knows a little bit about losing close ones to the Patriots. In 2009, the Bills held a 24-13 lead on a Monday night season-opening game at Gillette – Brady’s first game back from knee surgery – with just 5:38 left. Brady threw a touchdown pass to Benjamin Watson to pull the Patriots within 24-19. Then McKelvin took the kickoff 33 yards – and fumbled.

Gostkowski, of all people, recovered it with 1:56 left. Fifty-nine seconds later, Brady found Watson for a 16-yard touchdown and the Patriots won an improbable game, 25-24.

You see, the Patriots have been doing this for a long time. They wait for the opponent to blink, then they strike.

New England now has a five-game lead in the division. They have a two-game lead over Denver and Cincinnati for the best record in the AFC and home-field advantage in the playoffs.

Buffalo and the New York Jets and the Miami Dolphins are fighting for their playoff lives because they haven’t figured how to consistently win, even when they don’t play their best.

The Patriots have. They commit penalties. They make mistakes. But they know how to win. They have Rob Ninkovich getting a sack in the final seconds to seal it.

It helps to have Brady at quarterback. It helps when your defense steps up and forces three consecutive three-and-outs when the game is on the line, like it did in the second half Monday.

They continue to win even as they lose players. Amendola was going to replace Julian Edelman, who broke his foot a week ago.

They need him to get healthy quickly because Denver looms in six days.

After that it’s Philadelphia at home then on the road to suddenly-hot Houston.

It won’t be easy to remain unbeaten. But one thing is certain, the Patriots won’t beat themselves.