KANSAS CITY, Mo. -- The New Orleans Saints blew it big time on Sunday.

They coughed up one opportunity after another in a 27-21 loss to the Kansas City Chiefs. A pick-six thrown by Drew Brees. A devastating fourth-quarter fumble by Mark Ingram. Almost too many killer penalties to count -- including an unnecessary roughness call against defensive tackle Nick Fairley late in the game.

And in the process, the Saints (2-4) squandered away all of that momentum they had built up with back-to-back wins over the previous three weeks.

“We’re not a good enough team to overcome some of those type of mistakes,” Saints coach Sean Payton said. “We didn’t do enough smart things in the end to give ourselves a chance.”

“That can’t happen against a team like this in this type of environment,” Brees added. “So we got what we deserved.”

Sure, the Saints were underdogs in this game. So a loss at Kansas City doesn’t necessarily doom their entire season.

But this was really an unforgivable performance for a team that talks all the time about having zero margin for error.

After taking two steps forward, the Saints essentially stumbled backward over their own feet with their sloppiest performance to date.

And now it won’t get any easier for them to climb their way back to .500 with a grueling schedule on the horizon (home against Seattle, at San Francisco, home against Denver, at Carolina on a Thursday night).

“I still feel like we are an ascending team and we are getting better. You’ve just gotta understand what gets you beat,” said Brees, who was both encouraged and frustrated by the fact that the Saints' offense played so well when they weren’t shooting themselves in the foot.

New Orleans outgained Kansas City 463 yards to 326 and the Saints were much better on third down (64 percent to 33 percent).

“But on the ones where we didn’t get points, it was either we turned the ball over or had penalties that killed the drive,” said Brees, who said he wished he had thrown his interception about a foot further to the right to give receiver Willie Snead a chance at it, instead of having it get tipped by safety Eric Berry and returned 48 yards for a touchdown by safety Daniel Sorensen for a 14-7 Chiefs lead late in the first quarter.

But as Payton often likes to say, everyone had dirty hands in Sunday’s performance.

The Saints lost the turnover battle 2-0, with both turnovers providing huge momentum swings.

Ingram’s fumble came at the Kansas City 7-yard line as he was fighting for extra yards at the end of a 6-yard run -- wasting a chance to close to within four points with 8:37 remaining.

As usual, the Saints’ defense had a lot of solid stretches but also gave up two game-changing plays -- a 46-yard TD catch by Spencer Ware on a short pass and a 38-yard TD catch by speedy receiver Tyreek Hill deep down the sideline.

Special teams got in on the act when kicker Wil Lutz mishit a kickoff in the third quarter that helped set up a Kansas City field goal drive and return man Tommylee Lewis muffed a punt return for bad field position before halftime.

But it was the penalties that might have been the most unforgivable -- especially Fairley’s 15-yard personal foul penalty that was completely unnecessary and away from the play on Kansas City’s final field goal drive with 2:26 remaining. Instead of third down, the Chiefs got a fresh first down.

"You can't do that stuff," Saints safety Kenny Vaccaro said. "Teams that do that end up at home during playoff time. ... It's a stupid play."

“Obviously it’s discouraging, because it’s not smart football,” Payton added when asked about Fairley's penalty.

Fairley declined to speak to reporters after the game.

That was hardly the only penalty, though, as New Orleans finished with 10 of them for 75 yards -- including two delay of game penalties that stalled two-minute drives in each half and a handful of false starts and offensive holding calls in the first half.

“We can’t do much worse,” Saints offensive tackle Zach Strief said while making the point that the team needs to realize just how good it can be -- since it nearly won despite all of those mistakes. “I mean, you watch that game and you’re like, ‘Oh my god, this is ridiculous.’ We’re saying the same thing. I’m on the sideline like, ‘I can’t believe that we’re shooting ourselves in the foot this much.’”

The Saints have enough problems without having to create more of their own the way they did Sunday.