Premier League goal-line technology saves ref who had no idea a shot just went in

Swansea beat Arsenal 1-0 on Monday in a game that would have ended 0-0 without goal-line technology.

In the 85th minute, Obafemi Gomis skipped in a header that looked like it was saved by Arsenal goalie David Ospina. On TV, the commentators even thought it hit the post:

After calling a goal kick, the referee was informed via an alert on his watch (the standard procedure in goal-line technology) that the ball had actually gone in.

Check out his reaction. He had no idea:

It was clearly a goal on replay:

Well across the line:

Here's the animation:

The world's biggest leagues were slow to adopt goal line technology. The Premier League didn't start using it until 2013.

This is the perfect example of why it's so necessary.