Manager Sir Alex Ferguson and assistant Carlos Queiroz have both condemned Cristiano Ronaldo for allowing himself to be provoked into the rush of blood that has brought him an automatic three-match ban - including Manchester United's derby clash with City on Sunday.
The brilliant Portuguese foolishly head-butted Portsmouth substitute Richard Hughes who had pushed him during a goalmouth melee in last night's 1-1 draw at Fratton Park.
And FA Cup final referee Steve Bennett, a yard away from the incident, had no option but to issue a red card - the third of Ronaldo's United career and the second from Bennett.
It means United face the Manchester derby without Ronaldo - who also sits out games against Sunderland and Tottenham - Wayne Rooney - out for two months with a broken foot - and four points behind title rivals Chelsea.
Even if they beat City they cannot overtake Sven-Goran Eriksson's team in the table and Ferguson blasted: 'Cristiano was provoked but he fell into a trap of intimidation and he has to learn from it.
'It is another big blow to lose but it has happened with him a few times.
'I've looked at the replay, which is inconclusive, but my take on it was that he responded to something. He should know that this is what other players do and he's got to tell himself that they are inferior to him and this is why they do it.'
Queiroz added: 'It was a difficult situation but we are always telling players not to react and keep a cool mind.
'The referee was right there and Ronaldo lost his temper. You cannot let that happen.'
Ronaldo's dismissal - Bennett also sent him off in a Manchester derby two years ago - came in the 84th minute, only seconds after Portsmouth's £7.2 million signing Sulley Muntari received his own marching orders for a second bookable offence.
The Ghanaian, who tripped Ronaldo for his first caution, went in late on Michael Carrick and again Bennett's decision was a no-brainer.
But Muntari will miss only Saturday's home game with Bolton, and Ferguson was clearly aiming his ire at the referee when he said: 'Ronaldo and Carlos Tevez were given no protection all night.
'Portsmouth got stuck in and we had to cope with some of their rough stuff but we still played some fantastic football.'
United drew 0-0 at home to Reading on Saturday and at City will be chasing their first win in six competitive games - not counting the Community Shield clash which they won on penalties.
They are still also unbeaten this season, of course, as are Pompey, although if anything rival boss Harry Redknapp faces even bigger personnel problems than Ferguson.
England coach Steve McClaren arrived at Fratton Park to run the rule over Sol Campbell - among others - but the Pompey captain missed out with a groin injury while right-back Lauren was another notable absentee with ankle trouble.
After Campbell's deputy Noe Pamarot limped off with a pulled hamstring, Redknapp said: 'We finished with a back four of entirely left-footed players.'
Having spent £23 million on seven summer signings, he revealed: 'Now we are down to 16 fit men for Saturday. Sol and Lauren are struggling and Linvoy Primus is miles away in his recovery (from a knee operation).
'But what a fantastic performance. United are a top, top team and any point you get off them is a bonus point.
'United played some great stuff but I changed it at half-time from one up with two wide attackers back to 4-4-2, and it worked.
'It was a typical Portsmouth performance. I took off Pedro Mendes and young Martin Cranie, who was making his debut, at half-time but they also did well.'
Carlos Tevez made his United debut - watched by his controversial agent Kia Joorabchian - the Iranian businessman whose conflict with West Ham over the player's ownership caused such an upheaval in the Premier League.
And when he set up a sweet scoring strike for Paul Scholes in the 15th minute it seemed the prelude to a strolling United triumph.
But Pompey showed the pluck and resistance which has brought them three victories in four of United's previous visits to Fratton Park.
Pompey poached a 53rd minute equaliser when Benjani, the striker with a reputation for not scoring, notched his second goal in two games with a bullet header.
They still had to endure breathtaking near-misses by Tevez and Nemanja Vidic before the fiery finale, and with new £6 million striker David Nugent missing a couple of chances an initially tepid clash turned into a memorable night.