The all-red outfits they donned for the first time Sunday drove home the point.
Playing nearly mistake-free for the second straight week, Smith threw for 223 yards and two touchdowns against the ball-hawking Dallas Cowboys, and the Chiefs defence held when it needed to in the fourth quarter to preserve a 17-16 victory.
"When you're trying to build something, you need to win games like this," said Smith, who also had a game-high 57 yards rushing. "These are the games you look at in November and December. You need these types of wins, not only the calibre of the win but the style of win.
"It's not always going to be pretty," he said, "but you have to find a way to bear down."
The Chiefs did that marvelously in the fourth quarter.
Dwayne Bowe's go-ahead touchdown catch and Ryan Succop's field goal had staked them to a 17-13 lead, but the Cowboys were on the move in the closing minutes. After Tony Romo threw three straight incompletions, though, Dan Bailey had to kick a 53-yard field goal.
The Chiefs regained possession with 3:55 left. Jamaal Charles helped them grind out a couple first downs, and a pass interference call on Morris Claiborne on third-and-10 gave Kansas City another set of downs. That kept Romo from having any time to orchestrate some late-game magic.
"We ask a lot of certain players on this team and they showed up," Chiefs cornerback Brandon Flowers said. "We did a great job of holding them down."
Romo, who was playing with bruised ribs, finished 30 of 42 for 298 yards. His favourite target was Dez Bryant, who had nine catches for 141 yards and the Cowboys' only touchdown.
"You got to realize, you can't forget all the work that you put in to go out and be a good football team," Bryant said.
The Cowboys (1-1) forced the New York Giants into six turnovers in their opener, but couldn't turn the same trick against Kansas City. After preaching ball security all week, the Chiefs got through their second straight game without throwing an interception or losing a fumble.
"Takeaways and points, man, on both sides of the ball. We try to eliminate the turnovers and we try to score points," Reid said. "It's as simple as that."
The Chiefs, coming off an uplifting win at Jacksonville, were amped for his first game as their coach at Arrowhead Stadium. A capacity crowd roared when they rolled onto the field in all-red uniforms, departing from traditional white pants to signify the start of a new era.
They kept on rolling, too. Kansas City marched 77 yards on the opening series, the highlight coming when Smith scrambled 17 yards on third-and-15 and executed a Fosbury Flop over a defender for a first down. Smith capped the drive with a short TD toss to Charles.
That's when the Romo-to-Bryant connection got on track.
Bryant outwrestled cornerback Brandon Flowers for a 53-yard catch that helped set up Bailey's first field goal. He then hauled in a short TD catch to give Dallas a 10-7 lead.
The Cowboys blocked Ryan Succop's 57-yard try to carry their lead into halftime, and then Bryant caught three more passes to set up another field goal in the third quarter. But the Chiefs answered when Smith hit Bowe on a 12-yard slant for a 14-13 lead later in the quarter.
Dallas fumbled on its next two possessions — Lance Dunbar coughed it up first and then Romo was strip-sacked by Ron Parker. But its defence stiffened each time, first forcing a field goal and then getting a sack from Bruce Carter to push the Chiefs out of Succop's range.
The Cowboys marched deep into Chiefs territory one last time, but again couldn't find the end zone. And when Romo got the ball back, there was hardly any time left.
"We had a good plan and did some things that gave us a chance to win this football game. We put ourselves in position, but we didn't," Romo said. "Ultimately, that's all that matters."
Notes: Cowboys TE Jason Witten had three catches to pass Shannon Sharpe for second-most among tight ends. Witten has 817 in his career. ... Chiefs LT Branden Albert hurt his left shoulder but returned to the game. ... Cowboys DE DeMarcus Ware and Chiefs DT Dontari Poe each had two sacks.
AP NFL website: www.pro32.ap.org