CHARLOTTE — Donte Jackson came into the game with a sore ankle. He rolled it again in the second quarter, and again later in the game. But a word kept ringing in his ears this week, and not being on the field when it ended wasn't an option.

"Oh, no, no, no, no," Jackson replied when asked if there was a chance he wasn't finishing this game. That's four nos, in case you're counting.

"I needed that one."

They all did. The Panthers have played good defense for a half, or even three quarters this season. But they haven't played four quarters like this all year, and they especially haven't played this way against Tom Brady.

That made a 21-3 win over the Buccaneers Sunday a cause for celebration for the Panthers, or at least as much of a celebration that's warranted when it improves you to 2-5.

A fourth-quarter field goal was the only points the Bucs got on the board, as the Panthers played the kind of game they've hinted at previously but hadn't delivered on.

The fewest points Brady had ever scored in nine previous starts against the Panthers was 17 in 2005, and it had been many more than that recently. In his four meetings with the Panthers in the last two years with the Buccaneers, Brady had won all four starts (combined score 150-63), throwing eight touchdowns and just one interception and completing 69.5 percent of his passes. According to NFL Media Research, the Bucs' 21.8-point differential against the Panthers since Brady arrived in Tampa Bay was the biggest against any team (minimum of four meetings).

So for the Panthers to make him look, well, ordinary, that was saying something. Brady completed 32-of-49 passes for 290 yards, but he didn't get in the end zone for just the sixth time in his career, and his pedestrian 81.2 passer rating was a representative summation of his day. He hit a few plays, but not nearly what he's used to, especially not against the Panthers.

"It means a lot. We know their high-profile players on offense; we know their ability to rack up a lot of points, a lot of yards both running and passing," Jackson said. "So to come in the Bank and hold a offense like that to three points and 2-of-12 on third downs, it's amazing.

"It just proves that we know what we could be. We just have to stay consistent."

When asked why it was different, Jackson pointed to a sign over the door next to his locker, a simple printout with a single word — FINISH.

It's not an accident. That was one of the words interim coach Steve Wilks kept using all week, and again on Sunday.

"I think the difference was the mindset; those guys wanted to finish," Wilks said.

"Look at the sign right there; it says finish," Jackson said. "That one on the door over there says finish. So that's been the emphasis. There's a lot of teams in this league that can play a good half of football. The emphasis for us was finishing.

"We're no strangers to playing good first halves. That's the thing coach has been saying all week, is just 'finish, finish, finish.' Whether it's practice and the last play of practice or the last period of practice, it was 'finish, finish, finish.' I guess that was just our mindset. When we woke up this morning, you could just feel the energy. When everybody got here to the stadium, you could feel the energy, and it was a good energy."

Of course, it almost didn't matter, as the Panthers got a break early in the game that allowed the late stuff to matter. On the second play of the game, Jackson slipped, and Bucs wideout Mike Evans was running wide open down the middle of the field. But he dropped what would have been an easy touchdown, and he knew it.

"No one play is the sole reason you lose, but that was definitely the biggest reason," Evans said. "I'd seen the life go out of us and it took me a while to get back playing. We were taught just to play the next play, but it was tough."

But after getting that gift, the Panthers continued to play with life throughout the day.

In the middle of the third quarter, with the team hanging onto a tenuous 7-0 lead, the Bucs drove to the Panthers' 25-yard line.

But on back-to-back plays, linebackers Shaq Thompson and Cory Littleton stopped running back Leonard Fournette for no gain.

"That was a huge fourth-down stop," Wilks said. "I think it was a momentum-builder for us, confidence-wise, to be able to stop those guys and get off the field. I thought the defense did a good job today."

That was a pretty extreme understatement by Wilks.

"Fourth down, they're going for it. As a defense, our mindset is we can't let them get that yard," Littleton said. "So, thankfully, I was able to contribute to it.

"Playing a complete football game. That's something we've been talking about doing all year long, and today we actually did just that. We're trying to stop them from scoring a single point, but we'll settle for three points."

Littleton grinned as he said it, because settling seems like an unusual concept, considering where the Panthers have been already this year, and what Brady's done to them.

"It always means a lot to do it against any team, because everybody's good," Littleton said. "But being able to do that today was special."

Defensive end Brian Burns sacked Brady early, helping to set the tone for the day. And for a guy who's openly said since the weekend he was drafted that he wanted to sack Brady, finally seeing number 12 on the ground meant a little more.

"I couldn't even do my damn pose because I was so excited," Burns said with a laugh.

Through the first six games of this season, the Panthers defense often ran out of steam late in games. They had allowed just 50 points in the first half, the fifth-fewest total in the league. But attrition was an obvious issue, as they struggled to get opponents off the field on third down while Carolina's offense struggled to stay on the field. Coming into Sunday, the Panthers had allowed a league-high 96 points in the second half.

"It's something that's been overdue. We should have been doing this. It's always been those one or two drives where we let go of the rope, and we were preaching on the sidelines, hold onto the rope. Stay locked in, so we can have a complete game," Burns said. "There's still some holes in there we can fix, but for the most part, it was a good game."

And it was one that no amount of pain was going to keep Jackson from finishing.

Starting cornerback Jaycee Horn wasn't able to play, and CJ Henderson wasn't able to get through the game with an arm injury. So Jackson, who had to get a new tape job and was hobbling at multiple points, wasn't coming out.

"I've felt better," Jackson said, after a game-high 10 tackles, the second most of his career. "My ankle's still bothering me a little, but it's getting there. As much as you want to keep playing, it's going to linger. The plan this week was great, they rested me this week, so I could go today. It worked. It kept it from knocking me out of the game. I rolled it sometime in the second quarter, and was able to un-spat and re-spat, and get back in. It was still lingering.

"But it felt good," the team captain said with a smile. "It definitely felt good to win."