CHARLOTTE — You can make it as conditional as you want — of course, it was the preseason; of course, the Bills weren't playing quarterback Josh Allen.

But a shutout is still the ultimate goal for any defense, so the Panthers weren't apologizing. The Panthers starters held the Bills to 89 yards in the first half of Friday night's win, in their most extensive work of the preseason.

That included a key fourth-down stop deep in their own territory, a Jeremy Chinn interception that took a quarter of the entire defense to bring down, and then the second and third units building on that, leaving the Bills with no points at the end of the night.

"It don't matter who's on the field, the ones, the twos, the threes, we all expect the same standard when we step on that field," Panthers linebacker Frankie Luvu said. "We try to hold everybody to that level and make sure the young guys learn that.

"This defense is young. Well, not young, but energetic. Relentless. Wanting people to fear us. Every time we step on that field, we take pride in doing our jobs."

They had some evidence of their improvement Friday night, in Luvu's play on fourth-and-1 from their own 8, stopping Bills running back Duke Johnson in his tracks. He came through with the kind of flash he's shown, and new safety Xavier Woods was there to help clean up the play. Woods laughed and said the entire defense feeds off Luvu's energy, and he's been here long enough to know to follow it.

"I just followed The Uce," Woods said, using Luvu's locker room nickname. "Uce got him low, and I got him high.

"We go out there to compete; you always want to do well. You build off that. It's a stepping stone to where we want to get to as a defense and a team."

"Man, we take pride in it as a defense, defending every blade of grass down there," Luvu said of the play. "Trying to challenge ourselves. As a defense, we take pride every time we step on the field.

"He (Woods) said on that play; he said, 'I was just following you.' I'm glad he did. Now I know that he's got my back."

Again, it would be a mistake not to point out the setting and the opponent and the calendar. But for all the strides the Panthers made last year, red zone defense was a consistent issue. So even if it was a preseason stop, there was something tangible about the boost that play gave them.

"You can build an identity on that," defensive tackle Derrick Brown said. "When your back's against the wall, nobody else to rely on but those 11 guys on the field, and you make something happen. . . .

"Our motto is, whoever we go against, we're going to give them our best. We're going to find our best. The last six weeks, we've been preparing, so we're going out to try to dominate, whether it's against ones or twos, just dominate the opponent in front of us."

The collective effort was there throughout the night, with defensive end Yetur Gross-Matos and defensive tackle Matt Ioannidis both getting hands on the pass that Chinn picked off in the first half. He also pointed to the job the reserves did keeping the Bills off the scoreboard.

"Proud of the way the whole defense played," Gross-Matos said. "Even the way the twos and threes were going in there, and not dropping off the standard the ones set."

Woods is new here, but he's fitting in quickly, establishing himself as a leader in a young secondary. Coaches have talked about the job he's done communicating across the defense, making sure everyone is on the same page, and for a night, it appeared they had things in a good place.

"I think we did pretty well; we communicated well, executed well, no breakdowns," Woods said of the game as a whole. "We just want to go out; we haven't got a lot of work as a whole group in a competitive situation. So to go out there with all 11 guys that were out there, that's big for us. Now we go build off that. . . .

"On the field, in the meeting rooms, just communicating with each other as one. That's what it takes to be a good defense, or a great defense, all 11 guys moving as one. That's a big theme for us, something we've emphasized."

The challenges will certainly get bigger as the weeks pass. But Friday night was evidence of progress. And that's the direction you want to be pointed in going into the regular season.