Gianfranco Zola has condemned the disgraceful scenes which marred West Ham's Carling Cup clash with Millwall at Upton Park.
Pitch invasions and ugly confrontations between rival supporters scarred the Hammers' 3-1 victory in the second round contest.
One man was stabbed in the chest near the stadium as chaos erupted, while police were forced to make a number of arrests as the disorder escalated.
Neil Harris had given Millwall the lead at Upton Park before a brace from Junior Stanislas, including an extra-time penalty, and a late effort from Zavon Hines sent the home side through.
The night was completely overshadowed, though, by the actions of certain supporters and Hammers boss Zola admits the trouble is the worst he has seen in his long and distinguished career in the game.
"I've been involved in difficult games and things happened. Here, I've played seven years and I've never seen it like this," said the Italian coach.
"It's certainly not good for football. I was completely shocked. Totally.
"I knew it was a game that meant a lot for the two sets of supporters, but I didn't imagine it like this.
"What can I say? I'm a sport man. I love the game. I love to go on the pitch and try and make it exciting for the supporters and enjoyable for everybody to watch. This was beyond my powers."
Millwall boss Kenny Jackett added: "I didn't fear for my own safety."
He added: "There were no Millwall fans on the pitch. They stayed where they were supposed to.
"There were a lot of people on the pitch. The lads gathered together and came to the sides, as they should have.
"I wasn't aware of the stabbing outside the ground. I'm very sad to hear that. We've got a passionate game in this country, but when it oversteps the mark then things have to be done."
West Ham have also released a statement vowing to punish those responsible for the mayhem on Tuesday.
"West Ham will fully investigate the deplorable scenes that took place during the Carling Cup tie with Millwall on Tuesday evening," the statement read.
"The club will not tolerate the unacceptable behaviour witnessed inside the Boleyn Ground and will take the strongest possible action against anyone found responsible, including life bans.
"As was the case before, during and after the match, we are co-operating fully with the relevant agencies, including the police."