The wild scene all went down during the Tottenham vs. Norwich City game in England ... where Hotspur star Dier had allegedly heard about some insults hurled his brother's way in the stands.

You can see in footage of the altercation ... 26-year-old Dier jogged along the sideline, jumped over the railing and beelined over more than a dozen rows of chairs to get to the fan to police everything himself.

Fortunately for all parties ... Dier was intercepted by security and other spectators before he could get his hands on his target.

After Dier and the altercation had calmed down ... Tottenham manager Jose Mourinho told reporters he didn't necessarily blame Dier for his actions.

"I cannot run away from the question and I think Eric Dier did something that we professionals cannot but, in these circumstances, something that every one of us would do."

Mourinhio added, "When someone insults you and your family is there, and your family gets involved with the person that is insulting you, in this case your younger brother, I think Eric did what we professionals cannot but, I repeat, did what we professionals cannot do, but did something that probably we would do."