CHICAGO – After Tom Brady’s final pass attempt hit the ground, Khalil Mack and Akiem Hicks shared a hug as they walked off the field.

The Bears’ Pro Bowl pass rushers earned those hugs. Tom Brady hadn’t seen a defense like the Bears.

The Tampa Bay Buccaneers quarterback has had a stellar start to the season for his new team. None of the previous four teams he played against had a man named Khalil Mack.

Mack had two sacks in the Bears’ victory, 20-19, over the Buccaneers on Thursday Night Football at Soldier Field.

Brady had the ball in his hands with a chance to drive his team down field and win the game. The Bucs wouldn't have had it any other way. The Bears defense simply finished the job.

"Man, these guys, it's a mentality or whatever," Mack said. "When our backs are against the wall, there's a lot of doubt out there, we believe in each other and we know in those moments that we can count on one another."

Mack's performance was the type of performance Bears fans crave from the Pro Bowl linebacker, and it was exactly what the Bears are paying Mack so much money for.

"You have a guy like Khalil that, every single snap, he’s bringing it and you just have to know that he’s coming," Bears coach Matt Nagy said. "The other guys feed off of that."

Thursday was easily Mack’s best game of the season. The Bears came up with stops when they needed to and gave their offense a chance to win the game. A key three-and-out late in the fourth quarter gave the Bears the ball back with enough time to drive down field and win the game on a Cairo Santos field goal.

Mack has been battling a minor knee injury all season. He was limited in practice for much of the first four weeks. He was finally taken off the injury report for the first time on Wednesday, and participated in full during practice.

It’s impossible to know how much the nagging knee injury bothered Mack in the Bears’ first four games. The stoic Mack does not make excuses for himself.

Either way, he was not bothered by the knee on Thursday.

At one point, he sacked Brady and chucked 320-pound Buccaneers offensive lineman Tristan Wirfs to the ground with one arm. It was akin to a mythological creature, not a mere football player.

The Bears sacked Brady three times, and disrupted him in the pocket often. James Vaughters had the third sack for the Bears, and Mack added a third of his own, but it was called off for a penalty.

Simply put, the Bears don't win that game without their defense because the offense struggled at times.

"We find ways to win, and it’s not always pretty," Nagy said. "We totally understand that. Using these next couple days and our coaching staff on offense to really figure out where we are, self-scout ourselves so that we can score more points and be better there, along with the quarterback change. But this is a big win for us, to be 4-1."

Defensive coordinator Chuck Pagano and the Bears defense passed what was arguably its biggest test so far. And that's saying something because the Bears defense has passed a lot of tests already.

The defense deserves credit. It has continued to come up with stops when the game is on the line. It did so in comebacks against the Detroit Lions and Atlanta Falcons. It did so when the New York Giants rallied late in Week 2.

And it did so again against Tom Brady and the Buccaneers.

"We love it that way, with the pressure on us," Bears linebacker Roquan Smith said. "So it was just about stepping up and making plays when we really needed to. That’s what good defenses do."

Chicago Bears