Fans who ran onto the pitch in Aston Villa's FA Cup quarter-final win over West Brom at Villa Park are "mindless idiots", says Baggies boss Tony Pulis.
An invasion by Villa supporters held up the tie in injury time and home fans also ran on at the end, while seats were thrown from the West Brom end.
Pulis expects the FA to investigate what happened during and after Villa's 2-0 West Midlands derby win.
"It's disgraceful. We don't want to see those scenes," said Pulis.
In a statement, the Villa board apologised to "the Football Association, the West Bromwich Albion directors, manager Tony Pulis and all his staff and players".
It added: "The club does not condone supporters invading the field of play under any circumstances.
"We are very disappointed that what should have been a very memorable and proud moment for our fans was marred by the actions of those who could not control themselves.
"They have let both themselves and their club down."
Two pitch invasions in five minutes
Referee Anthony Taylor was forced to halt the game in stoppage time, with Villa leading 2-0, as home fans spilled onto the pitch.
Many fans remaining in the stands booed the pitch invaders and chanted for them to leave the field.
The match resumed after a short delay, before another invasion after the final whistle.
'Players were put in danger'
Pulis said the pitch invasions should lead to Aston Villa reviewing their security measures.
"If you're Villa, you need to look at the stewards as they came over to our fans and there was nobody there," he said.
"It puts players in danger and you don't want to see that. You would see that in the 1970s and 80s and you don't want to see that again.
"I'm sure the FA will look at it without me poking my nose in. If we had a lot of stewards it would be sorted out."
Villa manager Tim Sherwood, whose team beat West Brom 2-1 in the Premier League on Tuesday, said he "could not condone the fans entering the field of play" but added: "I have to say, to be totally honest I can understand their emotions.
"They have just beaten their local rivals twice in a week, once in an FA Cup quarter-final, and emotions are running very high, but the club can't condone those actions, especially if anyone was touched."
'People were biting me'
Aston Villa goalscorer Fabian Delph was surrounded by fans at the final whistle.
"My armband got nicked, someone got my left boot, but I could appreciate the relief the fans are feeling after a result like that," he told BBC Sport.
"It was dangerous. Someone tried to take my boot off. People tried to kiss me and were biting me. It was scary."
'Like a scene from the 1980s'
Mark Lawrenson, who was co-commentator for the match which was broadcast live on BBC One, said: "Why would you do this? You're winning, absolutely stupid. Loads of villages have lost their idiots tonight. Absolutely bonkers.
"It's like a scene from the 1980s all over again. Absolutely ridiculous."
'It could kill someone'
Match of the Day studio pundit Kevin Phillips said: "I think there's going to be repercussions for Villa here as I don't think there was enough police or stewards to stop them coming on the pitch.
"Seeing seats fly down from the stands… it could kill someone. They'll identify these people and they should be banned for the rest of their lives."
Analysis - Phil McNulty at Villa Park:
"The ill-feeling between these two fierce West Midlands rivals provided a tense undercurrent throughout and boiled over in a threatening atmosphere over the final few minutes.
"West Brom fans, angered by Claudio Yacob's unjust red card and a second Villa goal from Scott Sinclair, threw several seats they had ripped out on to the pitch.
"The response from Villa fans was that premature pitch invasion, although it should be stressed it was a minority and thousands of their own supporters vented their fury against them.
"It was, in fact, only a minority on both sides but still a poor advert for the game, right down to West Brom sub Callum McManaman reacting angrily to being jostled by Villa fans at the end."