It was the type of blunder-filled play that looked like an absolute game-changer.
"You see him throw it 10-yards, 15-yards ahead of you, you're like, oh we got 'em, all our guys are down there," said Cowboys defensive end David Irving with a wry smile, before adding, "and they wind up doing some crazy stuff."
By crazy, he meant stuff rarely seen and unbelievable.
Instead of dialing up a traditional Hail Mary play with a pass to the endzone, Alex Smith threw a short pass to receiver Tyreek Hill, who had two tight ends and a receiver blocking for him.
What happened next made seven Cowboys defenders look absolutely foolish.
Hill made a quick cut to the left, beating cornerback Orlando Scandrick, then cut up field following his blocks perfectly, before making an ankle-breaking move to beat linebacker Anthony Hitchens.
For 29 minutes and 58 seconds, the Cowboys played near-flawless defense, but the 56-yard touchdown as the first-half expired threatened to completely ruin the effort.
"I definitely said, 'Are you kidding me?,' and came in a little upset that they got those points on the board," said Cowboys defensive end Tyrone Crawford.
"Impossible," CBS play-by-play man Jim Nantz yelled on the broadcast. "How did they do that?"
And former Cowboys quarterback Tony Romo, doing color commentary for the game, shrieked, "Oh my gosh!"
"Guys missed a couple tackles," said linebacker Sean Lee. "We have to find a way in those situations to tackle better."
A play like that causes such a momentum swing that could have affected the Cowboys defense for the rest of the game. Instead, they huddled at the half, defensive leaders spoke, and they were eventually able to dial it back up.
"Just let it go," was the sentiment according to Crawford, "and just get back to what we were doing before that play."
Before that play, the Cowboys defense had been lights out, allowing the NFL's third best offense coming in just one field goal on the previous five drives.
"We had a great game plan. They got one play, but stick to our game plan and everything would be fine, and it was," said rookie defensive end Taco Charlton, who notched his first career sack in the fourth quarter.
The game plan shut down league-leading rusher Kareem Hunt; just 37 rushing yards on the day.
The Cowboys also forced Chiefs Quarterback Alex Smith into his first interception of the season.
And instead of folding after a gut-punch, this Cowboys defense showed uncommon resilience.
"You know that's one of our things on this team, fight to the finish," said Crawford.
"I think we are building to be a really, really good defense," said Lee. "I think we have the talent. If we can continue to stay healthy, play together, and continue to improve, I think we can be very, very good."
For all but a few moments in this contest, the Cowboys gave every indication that should be the case.