Second City derbies between Birmingham City and Aston Villa always tend to be lively and Sunday's game at St Andrew's was expected to follow suit.
Both clubs currently lie in mid-table with not much to play for, so pride was mostly at stake.
However, within 10 minutes the game descended into chaos as a Birmingham fan ran onto the pitch and punched Jack Grealish from behind.
And yes, you've read that right.
The shocking footage below shows Grealish minding his own business before the fan sends him flying with a sucker punch.
"This is disgraceful, an utter disgrace," shouts the commentator as Villa players swarm the fan, who will no doubt be punished for his disgusting act.
Luckily Grealish didn't look hurt from the incident and was able to play on, while the fan was escorted and booed off the pitch.
More to follow.