The video Assistant Referee (VAR) has been a big talking point among Premier League fans since its introduction to the league at the start of the season.
There has been a number of controversial incidents involving the newly introduced technology, but the system proved its worth at Old Trafford this evening by overturning an incorrect call which would have otherwise stood.
In the second half of the match between Manchester United and Arsenal, Pierre-Emerick Aubameyang appeared to have broken the offside trap in order to finish nicely past Red Devils' goalkeeper David De Gea, only for the celebrations to be cut short by the linesman's flag.
However, replays clearly shown that the Gabon international striker was being played onside by Manchester United defender Harry Maguire, who was attempting to step up to play his opponent offside.
After going to a VAR check, the goal was awarded to Arsenal by referee Kevin Friend, sparking scenes of celebration among Arsenal fans and players much to the bemusement of the majority of fans at Old Trafford.
The goal drew the Gunners level after receiving a hammer blow just before the half time whistle as Scott McTominay's shot sailed past Bernd Leno.
After scoring the equalising goal, Arsenal fans took to social media, and there was one thing they were talking about.
The goal took Aubameyang to seven goals in seven appearances in the Premier League so far this season.
