Over the last week, we went through the 10 plays that shaped the 2014 season for the Detroit Lions. Here is the No. 1 play.

View the other plays that shaped Detroit’s season.

The play: Leading 20-17 in the fourth quarter, the Lions decided to throw on a third-and-1 from the Dallas 46-yard line against the Dallas Cowboys in the playoffs in January. Matthew Stafford threw a deep pass on the left side to tight end Brandon Pettigrew, who was not used much in the passing game in 2014. The man defending Pettigrew on the play, linebacker Anthony Hitchens, had a flag thrown on him for pass interference, which would have given the Lions a first down. Then, the officiating crew picked up the flag after assessing the penalty, turning a Detroit first down into a Detroit fourth down.

The situation: The Lions had played well throughout the game, although they pulled back from an aggressive first half where they thoroughly outplayed the Cowboys. This was a critical juncture in the playoff game because had Detroit picked up a first down, it would have started to creep into field goal range and also been able to continue a drive that been milking the clock. The controversy came from what the officials did after, by throwing and then picking up the flag. In the days after the game, NFL officiating czar Dean Blandino said a flag should have been thrown on the play – but not necessarily for pass interference. It should have been for defensive holding. That would also have given Detroit a first down to extend the drive.

The reason it mattered: There are many reasons that it mattered, mostly because of what happened after. Take the postgame controversy aside and look at what it did to the Lions. After Jim Caldwell decided to punt instead of going for it on fourth-and-1 – a questionable decision on the Cowboys side of the field – the Lions unraveled. Sam Martin shanked a punt 10 yards. The Lions then did what they had not done for much of the season, allowed a team to pull off a long, late drive against them, including two defensive holding penalties to extend the drive. It was the start of the end of Detroit’s season.

What Caldwell said the next day: "The fact of the matter is it is a controversial call. And without question was one that [was] probably not officiated correctly, in my estimation."