GLENDALE, Ariz. -- The Chicago Bears felt they had a top-10 defense last season.

This year, the bar is set much higher -- and rightfully so.

The driving force behind the Bears’ 2-1 start is the defense, which forced four more turnovers (on four consecutive series in the second half) in Chicago’s 16-14 come-from-behind win over the Arizona Cardinals.

“For our defense, three weeks in a row now they’ve done special things,” coach Matt Nagy said on Sunday.

Chicago is used to watching the Bears play a “special” brand of defense. From Dick Butkus to the ’85 Bears to Lovie Smith’s Cover 2 that featured Hall of Famer Brian Urlacher, Lance Briggs and Charles Tillman (to name a few), the Bears have often been synonymous with defense.

But the defense tanked the year after Smith left, and the Bears had few difference-makers on that side of the ball -- until now.

This Bears defense already has five interceptions, 14 sacks, two touchdowns and seven forced fumbles on the young season.

“When I say special, our guys and our coaches, they feel that right now,” Nagy said. “They feel that they can be in a different league of their own but it takes hard work.”

Chicago has done an admirable job collecting talent on defense.

The Bears used free agency to add linebacker Danny Trevathan, defensive lineman Akiem Hicks and cornerback Prince Amukamara.

General manager Ryan Pace then turned to the draft for linebacker Roquan Smith, safeties Eddie Jackson and Adrian Amos, and outside linebacker Leonard Floyd.

But the game-changer for the Bears was trading for Khalil Mack prior to Week 1.

Mack’s impact is felt on virtually every snap he plays. A former NFL Defensive Player of the Year, Mack had a game-high two sacks against the Cardinals and currently leads the Bears with four sacks.

But even when Mack fails to reach the quarterback, he manages to help the cause.

Arizona chose to triple-team Mack at times, but all that did was free up Hicks, who delivered a solid hit and sacked Cardinals quarterback Sam Bradford.

So far, Mack has recorded a sack and forced fumble in all three games.

The last player to have a sack and forced fumble in three straight games? Mack, who did it from Week 12 to 14 in 2016, according to ESPN Stats & Information.

“I’m thrilled. ... I’m blessed to be in the position I’m in,” Mack said. “The will to win, you see it, especially in the back end, the linebackers up front, just everybody is jelling together. It’s a brotherhood. Something special is going on.”

It's hard to argue with that last sentence.