Japan just beat world number one Ireland at rugby and the fan reactions are priceless

In sport, incredible underdog stories are what dreams are made of.

Every so often, a true David vs Goliath moment happens which makes everyone realise exactly what’s so amazing about sport.

The Japanese rugby team discovered this not long ago when they stunned South Africa 34-32 in 2015.

But now the World Cup hosts have done it again.

Playing their second game of the Rugby World Cup, the host team have pulled off another stunning upset, defeating Ireland 19-12 in a nail-biting match.

Naturally, given the huge upset, social media has a lot to say. People can hardly believe that Japan managed to pull off such huge win over the world's top ranked team.

The reaction of the team was priceless...

Not to mention the fans...

But then the tweets, memes and reactions came rolling in.

Though thankfully Ireland have been gracious in defeat. Irish Rugby tweeted to say that japan are "worthy winners".

More: This video of Steve Bruce getting in and out of chairs is very funny