The ball was in the air, Tommylee Lewis was turning to catch it -- then he was taken out of the air by Nickell Robey-Coleman.
Fans initially reacted to what looked like blatant pass interference, but the loudest reaction came when they realized there was no yellow flag on the field. The refs opted not to call a penalty on the play, a 3rd down play deep in Rams territory.
With the no-call, the Saints were forced to settle for a field goal with just under two minutes remaining. The Rams were able to drive the field and kick their own field goal to send the game to overtime time 23-23, eventually winning on a Greg Zuerlein field goal from 57 yards out.
The lack of a call, one likely to be talked about for years to come, drew swift and intense reactions on social media both during the game and immediately after.
Scroll below for some of the best reactions from the game. Can't see the feed? Click here.