'But for no reason these supporters clambered over a wall and 22 empty rows of seats to get at those sitting in the main stand. The stewards did an excellent job. They have their own response team and dealt with the problem very well until my officers joined them, but it did take some time to restore order.'
In fact, the violence took 13 minutes to quell, as police, wearing riot helmets, waded into the core of the hooligans, many officers throwing punches themselves.
The FA will await referee David Elleray's report on the trouble but it is unlikely that Manchester City will face a fine. Coventry chairman Bryan Richardson said: 'We will ban for life anyone found to have been involved.'
Substitute Goater took City into the fifth round with a powerful header beyond keeper Magnus Hedman from Tony Grant's corner.
Coventry almost scored 11 minutes into the game when Jay Bothroyd skipped away from Nicky Weaver, but Scotland defender Paul Ritchie got in a face-saving tackle for the home side. A minute later Coventry were again inches away when John Eustace's effort thumped the post after a clever drag-back by Craig Bellamy - but the longer the game went on, the less assured the visitors looked.
City's Paulo Wanchope was clearly unhappy at being replaced by Goater in the 71st minute - but the switch was, ultimately, to prove the deciding factor.