This was the play that ignited the KC Chiefs’ latest superb defensive effort vs. Saints

Chiefs safety Bryan Cook got things started. The rest of the Kansas City defense, especially when it came to stopping the run, also played a major role ... again.

The Chiefs defeated the New Orleans Saints 26-13 on Monday Night Football at GEHA Field at Arrowhead Stadium in what is becoming the usual manner: They held their foes below their season averages and bottled up the opponent’s top running back while also getting enough pressure on the quarterback.

All of that enabled the Chiefs play with the lead for an entire game for the first time this season, beginning with Cook’s athletic play.

On the game’s sixth snap, Saints quarterback Derek Carr, backpedaling under pressure, lofted a floater toward receiver Rashid Shaheed. Cook was closer to the descending ball than its intended target — but he still needed to leap, twist and secure the catch, while falling with his back parallel to the turf.

Cook’s interception made certain that for the first time this season the Chiefs’ opponent wouldn’t score on its first possession.

“At first I thought I misjudged it,” he said. “It was floating a different way, and I had to adjust to it while it was in the air.”

The interception, the second of Cook’s three-year pro career, was the start of a Chiefs possession that resulted in a touchdown. Finally, the Chiefs had taken an early lead.

“That was the important thing about it,” Cook said. “We’ve been getting off to slow starts on defense. This time we made a play and cashed in.”

The Saints entered the game with one of the NFL’s most productive offenses, leading the league in scoring at 31.8 points per game and yards per play at 5.74. They also ranked second in third-down conversations, at 53.2%, and running back Alvin Kamara led the NFL in yards from scrimmage per game: a stout 134.

New Orleans fell well below those averages Monday. Perhaps most impressive for the Chiefs, the Saints managed a sum 46 rushing yards as a team, with Kamara held to just 26 on 11 carries (he added 40 yards on six receptions).

“Dominate the line of scrimmage,” Chiefs linebacker Nick Bolton said. “We mixed up some different looks, some different fronts and confused their blocking a little bit. We won more one-on-one blocks than they did.”

Bolton finished with a team-high 11 stops, but this was a group effort. Interior players who didn’t fill up a stat line — Chris Jones with two tackles, Mike Pennel with one, Tershawn Wharton with the team’s lone sack — helped form a wall that the Saints couldn’t penetrate or work around.

The effort continued a trend that started in the opening game, when the Chiefs held Derrick Henry of the Baltimore Ravens in check and followed that with winning performances against other featured running backs — including the Bengals’ Zack Moss, the Falcons’ Bijan Robinson and the Chargers’ J.K. Dobbins.

Add Kamara to the list.

Through five games, the Chiefs have yielded just two rushing touchdowns and 3.7 yards per carry. Both marks rank in the NFL’s top five.

“It’s a mindset with this team,” safety Justin Reid said. “It comes from a motto for this team, ‘Demanding better.’”

As in, better than last year, when the Chiefs’ defense took at least as many bows as superstars Patrick Mahomes and Travis Kelce and the rest of the offense en route to the franchise’s second straight Super Bowl championship.

Through five games, this defense appears to be just as sturdy, if not more so. On Monday, it started with a pick.