Watford went into their clash against Chelsea at Stamford Bridge full of confidence.
Not only did the Hornets beat Arsenal last week but they were actually above the champions in the league table.
And that confidence was evident in the early stages in west London.
Marco Silva’s side knocked the ball around nicely and looked to attack Antonio Conte’s men.
However, things soon changed.
After a short corner, Eden Hazard found Pedro who curled the ball delightfully in off the far post.
It was just beautiful.
But it shouldn't have counted.
Well, because Chelsea should never have been awarded the corner in the first-place.
Hazard reached the byline with Miguel Britos in pursuit.
The Belgian attempted a drag back but accidentally back-heeled the ball off the pitch for a goal-kick.
However, the assistant referee inexplicably gave a corner - despite only being a couple of yards away from it.
Watch: Why it shouldn't have counted
Take a look:
Dear, oh dear.
Whatever your view on video assistant refereeing, surely it would help in circumstances like this.
The assistant referee was clearly guessing after taking his time to make his decision. A quick look at the footage and Watford would have rightfully been given a goal kick just seconds later.
Silva and his players will certainly be wishing technology in football was more advanced…
But Watford came from behind against Arsenal last weekend and will be hoping to do something similar this week.
After all, Chelsea failed to hold onto a two-goal lead in midweek against Roma, drawing 3-3 after being 2-0 ahead.