FOXBOROUGH — What happened on an 82-degree night in America’s heartland sparked immediate questions and criticism, then spawned a slogan that became a rallying cry, which was tweaked according to week and copied by mouth and put on shirts and posters, even after the Patriots rode it all the way to victory in Super Bowl XLIX.

A loss, of all things, got the ball rolling. But it wasn’t just any loss. When the Patriots visited Kansas City for a Sept. 29, 2014, game against the Chiefs, it produced New England’s most lopsided defeat in more than 11 years, a 27-point thrashing that had scribes scrambling for the media guide, and fans wondering how such a scenario could ever occur.

We revisit Chiefs 41, Patriots 14 because Saturday marks the first time the teams will have met since then. That one was just a Week 4 matchup. This one holds much greater importance; the winner at Gillette Stadium advances to the AFC Championship game.

Counting the preseason, the Patriots have played 35 games since losing to the Chiefs on “Monday Night Football.’’ They’ve gone 27-8, winning their fourth Super Bowl and two more division titles along the way. But now, days before embarking on what they hope will be a second straight trip to the Super Bowl, the Patriots are being asked about the on-field low point from what became a championship season.

“They played really well that night. We didn’t play very well. Hopefully we can flip the script,’’ said Tom Brady, who threw for 159 yards before being removed from the game after an interception in the fourth quarter was returned for a touchdown. “That’ll be the opportunity we have.’’

Both coaches this week, as you might expect, have downplayed the relevance of last season’s game. The Chiefs are on an 11-game win streak, while the Patriots lost their last two, and went 2-4 after a 10-0 start. Rosters have changed — although the Patriots will be expected to suit up 16 of the 22 starters from last year’s game at Kansas City.

Anything that could have gone wrong for the Patriots a year ago against the Chiefs went wrong. Kansas City built a 27-0 third-quarter lead, holding the Patriots to five straight punts to start the game, followed by a fumble recovery, then the first of two interceptions. It was 41-7 before a Jimmy Garoppolo-led touchdown drive in the fourth quarter allowed the Patriots to avoid their most lopsided loss under Bill Belichick. (That remains 31-0 at Buffalo to start the 2003 season.)

Losing to the Chiefs dropped the Patriots to 2-2, and prompted analysts and columnists to speculate whether the long, successful run that Belichick, Brady, and the Patriots had been on for 15 years was coming to an end.

Days after the loss, Belichick found a catchphrase and kept bringing it out at a midweek news conference, when more probing questions about how the Patriots would rebound from such a loss — or if they could — were being asked.

“We’re on to Cincinnati,’’ Belichick kept repeating.

The Bengals were next on the schedule, and the Patriots received the coach’s message. They had a focused, spirited week of practice following the loss to the Chiefs, then went out and blew out Cincinnati, 43-17, the first of what would become a seven-game win streak. Five of the wins were by at least 22 points.

Kansas City has had more roster turnover than the Patriots, expecting to have only eight of the 22 starters from last year’s game available on Saturday. But among them are three players the Patriots still have to deal with: Quarterback Alex Smith (who went 20 for 26 for 248 yards and three touchdowns in the game), running back Knile Davis (game-high 107 rushing yards), and tight end Travis Kelce (eight catches, 93 yards, touchdown).

Watching film of last year’s game has been part of the Patriots’ preparation this week. It hasn’t been the fun part, though.

“It wasn’t one of our finest outings, but I think history is a great teacher and we can learn from the way that game played out last year,’’ special teams captain Matthew Slater said.

Added Belichick: “We’ll definitely look at that game. It was a pretty dominant performance by Kansas City, so I’m sure that there are things from that game that they may try to do or that they may feel like they can still do or want to do what they did in that game.’’

According to Smith, both teams will be doing that.

“I think a lot’s been made of that tape,’’ said the Chiefs quarterback. “It certainly was quite a while ago, so obviously some guys are still there, there is carryover, and both sides are watching it.

“Both take things from it and try to play the chess match off it, of ‘How are they going to combat this and stop that,’ and vice versa. There’s a lot more to get prepared for between now and then.’’

Losing to the Chiefs, strangely, helped the Patriots have the kind of season they ultimately had; Belichick has said the second half of the game — in which the Patriots were outscored, 24-14 — gave the coach what he needed to see in terms of his team’s willingness to compete.

What each team learned, if anything, from last season’s meeting will be unveiled Saturday.

“The actual loss of the game, no, I couldn’t care less about,’’ said safety Devin McCourty. “But I think it’s always good to go back and see when a team has success against you.

“I’m sure they’re going to turn on the film and say, ‘This worked, that didn’t work, maybe we need to attack that and try it again or get to it in a different way.’

“I think that’s always good to go back and look at, just from an X’s and O’s standpoint. But the actual emotion of the loss, no, I couldn’t care less about.’’

Losing to the Chiefs this year will not create the same effect. It would be far more emotional.

?Chandler Jones had medical emergency on Sunday. D5

Michael Whitmer can be reached at mwhitmer@globe.com. Follow him on Twitter @GlobeWhitmer.