ALLEN PARK, Mich. — By the Detroit Lions’ own lackluster standards, their defense has been historically good so far in 2014.

Detroit has allowed just 1,624 yards through the first six games, 270.7 per game, the team’s lowest average since 1991. They Lions have given up just 82 points, their fewest through six games since 1970.

The Lions rank first in the NFL in yards allowed per game and points allowed per game (13.7).

They recorded eight sacks in Week 6 against Minnesota, reaching that total for the first time since 1997. They rank first in the NFL with 20 sacks.

The defense should face its biggest test of the young season Sunday when the Lions play the New Orleans Saints, who lead the NFC with an average of 442.8 yards per game. The Lions held their past four opponents to 17 or fewer points, the first time they did that since 1995, but making it five straight against quarterback Drew Brees and company won’t be easy.

“Obviously, it’s a challenge for us, but we’re going to be up for it,” free safety Glover Quin said. “We feel like we’re prepared. We feel like we understand the moment and what’s going on.

“Hey, they’re the No. 1 offense; we’re the No. 1 defense. Let’s go to battle.”

The success on defense starts with defensive tackle Ndamukong Suh, who is playing at an All-Pro level once again. Statistics don’t often show Suh’s impact, as he has three sacks and just 15 tackles this season, but he also leads NFL defensive tackles with 15 quarterback hurries, according to Pro Football Focus.

“The big thing is the attention that he draws, I think, has a positive effect on the rest of the guys,” coach Jim Caldwell said. “Most of the guys can count on a one-on-one in terms of pass rushing and then also defeating blocks in the run game because of him.”

The Lions also are able to rely on more consistent play from defensive tackle Nick Fairley and the ends. George Johnson, who spent most of 2013 as a free agent, has been a revelation with four sacks as the No. 3 end, and starter Ezekiel Ansah has four sacks in his second season.

The linebackers and defensive backs are playing well, too, despite some key injuries, particularly to middle linebacker Stephen Tulloch and nickel cornerbacks Bill Bentley and Nevin Lawson. First-year coordinator Teryl Austin, though, is instilling the right mindset for any player to step up.

“Trust your teammates. Do your job. Don’t try to do too much,” strong safety James Ihedigbo said. “Don’t try to be out there jumping routes and playing outside the defense. Do your job, and good things will happen.”