KANSAS CITY, Mo. (AP) -- The biggest reason the Kansas City Chiefs are the last remaining unbeaten team through the first four weeks of the NFL season is that someone long ago decided games should be 60 minutes.

The Patriots sure wish they lasted 30. Ditto the Redskins.

The Chiefs showed their second-half chops once again on Monday night, rallying from an early 10-point deficit against Washington.

Harrison Butker kicked the go-ahead 43-yard field goal with 8 seconds left, and Justin Houston returned a fumble for a punctuating score on the final play of the game, to cap another remarkable fourth quarter and keep the Chiefs perfect on the season.

"Especially a fourth-quarter game like that, it feels like we've had just about every game that we've started off here be pretty close," Chiefs tight end Travis Kelce said. "I mean, it's just to see this team finish, man, it's unbelievable."

Indeed, the Chiefs are building a reputation as the ultimate closers.

They trailed New England 17-14 at halftime of their season opener in Foxborough before a 21-0 fourth-quarter binge resulted in a 42-27 victory. They led Philadelphia just 6-3 at the break in their home opener before a big second half resulted in a 27-20 win. And they led just 17-10 last week against the Chargers before pitching a second-half shutout for a 24-10 victory.

All told, the Chiefs are outscoring opponents 54-13 in the fourth quarter this season.

"We knew we were better than that," running back Kareem Hunt said of the rough start against the Redskins, which included a series of missed blocks and penalties that put the Chiefs in an early hole.

"We just had to keep coming out and fighting," he continued. "Those guys knew we had a lot of football left in the game. We came back from 10 against the Patriots. We just had to keep fighting."

It was a fight to the end, too.

The Redskins took a 17-14 lead on a touchdown pass midway through the third quarter, then tied the game with 47 seconds left on Dustin Hopkins' 40-yard field goal.

But quarterback Alex Smith added another chapter to an already storybook season by hitting Albert Wilson for a 37-yard gain on a broken play, and that put Butker in position to drill the go-ahead field goal.

Oh, and about the kicker: He was claimed off the Carolina practice squad earlier in the week to replace the injured Cairo Santos, and missed his first career field-goal attempt in the first half.

He bounced back to hit three in the second, including the most crucial one with time running out.

But that's the way the Chiefs' charmed season has gone.

Lose running back Spencer Ware to a season-ending knee injury in preseason? Hunt emerges as a star.

Lose stalwart safety Eric Berry to a ruptured Achilles' tendon in Week 1? Daniel Sorensen turns into a reliable playmaker.

Lose starting center Mitch Morse to a foot sprain? Zach Fulton is there.

"We have a tremendous amount of leaders on this team," Chiefs wide receiver Tyreek Hill said, "and they do a good job of being vocal in both huddles. I think once that translates, it helps a lot."

The Chiefs are 4-0 for only the fourth time in franchise history, and first time since 2013, when they won their first nine games in coach Andy Reid's first season in charge.

It's the third time in Reid's 19-year coaching career that he has started 4-0.

Reid was quick to turn his attention to next week, though. Their game Monday night means they won't have their usual day off this week to celebrate their latest victory, instead forcing them to dive right into preparations for another tough test Sunday night in Houston.

The message seemed to get through to the guys in the locker room.

When defensive tackle Chris Jones was asked about the 4-0 start, he replied: "That's not important right now. The most important thing is getting prepared for Sunday."

NOTES:Reid had no injury update Tuesday on RG Laurent Duvernay-Tardif, who hurt his knee against the Redskins. If he's unable to play next week, Parker Ehinger might be in the mix. He's been recovering from a torn ACL sustained last season and has not been available. "We'll see," Reid said, adding that backup Jordan Devey performed well Monday night. "We have some choices there." … Reid said he had not seen video of cornerback Marcus Peters yelling a profanity at the crowd Monday night, but "I'll look at it and go from there."