However, a small pocket of Birmingham supporters APPLAUDED the incident as their fellow Blue was hauled off the pitch.
The outrageous reaction flew in the face of how the majority of fans responded to the encounter on social media.
"Prison. Full extent of the law needs to be applied here; this cannot be allowed to set a precedent. What a shameful day for football," wrote one furious Twitter user.
Another wrote: "How can this be allowed to happen. Assault charge and banned for life surely."
What some Birmingham fans did after Aston Villa ace Jack Grealish was PUNCHED is just SICK (Image: SKYSPORTS)
What some Birmingham fans did after Aston Villa ace Jack Grealish was PUNCHED is just SICK (Image: SKYSPORTS)
A third added: "Attacks from behind, cowers on the floor when the rest of the team show up but gets his confidence back when a steward is protecting him…"
A supporter took aim at the fans who applauded the pitch invader, saying: "Does he think he’s a peaky blinder or something, what a tool and then for them to cheer him."
"Absolutely disgraceful, what’s happened to football over the last few weeks," said a fan, bearing in mind recent incidents in the Scottish Premiership.
A Twitter user raged: "'Fan' that’s no fan. Ban him for life and better still lock him up. Disgraceful!!!"
Invalid email
We use your sign-up to provide content in ways you've consented to and to improve our understanding of you. This may include adverts from us and 3rd parties based on our understanding. You can unsubscribe at any time. Read our Privacy Policy
What some Birmingham fans did after Aston Villa ace Jack Grealish was PUNCHED is just SICK (Image: SKYSPORTS)
What some Birmingham fans did after Aston Villa ace Jack Grealish was PUNCHED is just SICK (Image: GETTY)
West Midlands Police confirmed the Birmingham fan who punched Grealish was arrested at St Andrew’s.
"ARREST: Following the incident on the pitch involving an attack on an Aston Villa player; a man has been arrested and en route to a custody block. Further details to follow," read their tweet.
Sky Sports pundit Gary Neville, meanwhile, suggested Birmingham ought to be punished with a points deduction or by having to play games behind closed doors.
"The club are going have to take a huge punishment for this to act as a deterrent in the future . A Points deduction or Empty stadium for 10 games!" read Neville’s tweet.