You knew Mahomes and the offense would be good. Defense made difference for the Chiefs

The Chiefs fired defensive coordinator Bob Sutton two days after they lost the AFC Championship Game to the New England Patriots in a shootout. The message was clear: The Chiefs, with one of the game’s best quarterbacks in Patrick Mahomes, required a defensive upgrade.

So that’s how last offseason began. Assistant coaches turned over. Veteran stars did not return. This was an overhaul, and a big one.

Advance in time to late Sunday afternoon. In the Chiefs’ locker room, defensive coordinator Steve Spagnuolo stood with his arm around safety Tyrann Mathieu, explaining what went right in the Chiefs’ 35-24 victory over the Tennessee Titans in this year’s AFC title game.

“This guy is special,” Spagnuolo said, motioning to Mathieu. “God brought us together, and I’m sure glad He did.”

These two figures who weren’t with the Chiefs last season reveled in the accomplishment. The Chiefs are going to their first Super Bowl in five decades and their improved defense is a major factor.

Mathieu, the All-Pro selection, had a hand in helping the Chiefs put the clamps on Titans running back Derrick Henry, who had been bulldozing opponents this season through the first two games of Tennessee’s postseason run.

Against the Chiefs, Henry finished with 69 rushing yards, his lowest total since going for just 63 against the Carolina Panthers on Nov. 3. The NFL rushing leader with 1,540 yards had been on a rampage with 377 rushing yards in postseason road victories over New England and Baltimore.

But on Sunday, Henry, after a 62-yard first half, gained only seven yards on three attempts after the break. Playing catch-up didn’t help Henry’s production after Tennessee fell behind 21-17 at halftime.

The Chiefs set out to stop Henry, who went for 188 yards and two touchdowns in the Titans’ regular-season victory over the Chiefs in Week 10. They added personnel to the box, which left them vulnerable to the play-action skills of Titans quarterback Ryan Tannehill.

Tannehill took advantage with 120 passing yards in the first half. He had thrown for just 160 yards in Tennessee’s first two playoff games.

The Titans scored on their first three possessions, taking a 17-7 lead. And then the Chiefs’ defense tightened up, allowing Mahomes and the KC offense to zoom ahead.

At that point, Henry was no longer a factor. The Chiefs had enough defense to keep the margin at two score after the taking a 28-17 lead early in the fourth quarter.

Helping Mathieu in the cause was Frank Clark, acquired last offseason in a trade with the Seattle Seahawks. Cornerback Bashaud Breeland and linebacker Damien Wilson are in their first season with the Chiefs, too. So is defensive tackle Mike Pennel. He arrived in mid-October.

They and other Chiefs defenders, like ends Alex Okafor and Emmanuel Ogbah, who didn’t finish the season on the field because of injuries, were part of a plan that was simple.

The Chiefs, with their abundance of offensive talent, needed new life on defense. And they found it.

Clark had a more descriptive term for the defense and its effort Sunday.

“We’re the baddest MFers on the planet,” Clark said, before turning his attention to Henry, the bruising Titans running back. “They said he’d get over 200 yards ... What did he get?”

Clark, like Mathieu, brought that kind of edge to the Chiefs’ defense, and general manager Brett Veach said none of the newcomers were here by accident.

“Last year when the season ended we knew we had work to do,” Veach said. “We put a plan together. I said in the offseason we didn’t pull names out of a hat.

“We identified Frank Clark, we identified Tyrann Mathieu. We were aggressive. We believed in the process, we believed in the guys we went after. We had to field a defense to complement our offense. We have one more game to go, but we feel like we’re in a pretty good spot.”

They’re in the ultimate spot, the Super Bowl. And it’s largely because the Chiefs became aggressive after last season and re-created their defense.