Kansas City, Mo. ? The half-eaten hot dog that sat on Gunther Cunningham’s desk overnight was looking awfully stale.

But a workaholic doesn’t want to waste precious minutes scaring up something fresh. And besides, everything tastes wonderful to a defensive coordinator the day after his team intercepts four of Tom Brady’s passes.

So Cunningham washed it down with a glass of water Monday morning and plunged right back into the work he so dearly loves: rebuilding a Kansas City defense that seems to be getting good enough for the Chiefs to become bona fide playoff contenders.

“I just saw this thing laying there and remembered I hadn’t finished it when I left the office about 7 o’clock last night,” Cunningham said with a laugh. “People would probably say it was terrible. But I don’t care. This defense is coming on. They’re getting better. The good part is they feel good about themselves.”

It’s been awhile since a Kansas City defense felt good about itself. Not since Cunningham was in his first tour of duty as defensive coordinator in the 1990s have opponents had much to fear when they lined up against the Chiefs. The past four years, the Chiefs have had one of the sorriest defenses in the league.

But with a host of newcomers, particularly at linebacker and defensive back, Kansas City seems to be turning the corner. A 26-16 victory Sunday over Brady’s injury-riddled New England Patriots was the third victory in four games for the Chiefs (7-4), keeping them squarely in the AFC playoff hunt.

“It’s been a long, long journey to get this to this phase,” Cunningham said. “I’m happy with the way they work during the week. I really like them. I hope the feeling is mutual.”

The defense has not played poorly since a 28-20 loss at San Diego that was not as close as the final score.

Since then, the Chiefs are 3-1 and have held Oakland to 263 yards, Buffalo to 209 and Houston to 259.

“We had that San Diego game and, boy, we didn’t tackle well,” Cunningham said. “But from that point on, we’ve really stepped it up.”