Referring to the 'black propaganda that has been obscuring what's actually happening at the BBC', Mr Birt called on Mr Tully and other critics to 'bury the hatchet and stop fighting old wars'.
Standing on the same podium at the Radio Academy's Festival in Birmingham from which Mr Tully had delivered his passionate attack 24 hours earlier, Mr Birt said the veteran correspondent's speech was 'dignified' and 'carefully argued'.
Mr Tully returned the compliment at a press conference afterwards, but said that Mr Birt had not answered one of his most critical points about the state of staff morale.
BBC staff - who made up about half the 400 audience - seemed impressed by Mr Birt's speech. Several said it was the best defence of his strategy they had heard him make. 'He did himself a lot of good today,' one said. 'If he'd made that speech six months ago he might not be as unpopular as he is.'
Mr Birt expressed his central argument like this: 'Change is difficult and the staff are critical of those of us who are pushing the pace.
'Could we - Canute-like - have done nothing and tried to hold back the tide of change? Was there a kinder, gentler way, as those who like to play to the gallery, to say what people like to hear, sometimes seem to suggest?'
Pointing to staff cuts and economies made at ITV, he asked: 'Do our critics think that any government would have stood by, with the world changing around us, and allowed the BBC to carry on without making similar efficiency savings?'
Mr Birt made a long defence of 'producer choice', the internal market system that has provoked much staff discontent. 'Producer choice has been caricatured as bureaucracy gone mad, with multitudes of business units exchanging contracts in a whirl of paper and computer messages. In fact, its introduction has been a remarkable success.'
Explaining the need for the new system, he said: 'We had an unwieldy, almost Soviet-style command economy, where money was allocated from the top to every activity . . . The whole system demanded from programme makers the skills of supplicants at some Byzantine court, rather than straight business dealing.'
He rejected criticism that the new system involved too many accountants. 'Who would ever run a company turning over more than most ITV companies without knowing where the money was?'
He said that the reforms in accounting procedures were already saving pounds 100m a year and that tight control of overheads could save another pounds 70m a year. 'No one needs to tell me how traumatic all this change has been for large numbers of those working in the BBC,' Mr Birt went on. 'I find concern and uncertainty in many of the places I go.'
But he refuted Mr Tully's suggestion that there was 'a very real sense of fear among staff that prevents them speaking their minds'. That had not been his experience in dealing with employees since arriving at the BBC in 1987. The views of the staff on the changes had been sought and will be published this week.
In what was seen as a reference to Mr Tully, Mr Birt denounced 'the odd old BBC soldier, sniping at us with their muskets, still telling nostalgic tales of the golden days when no-one bothered much about management, when all was creativity and romance'.
And he ended with this call: 'If you really care about the BBC, help us with your support as we come to the climax of the Charter Review debate. Resist the disinformation, the half-truth, the caricature, the propaganda.'
There was a long round of applause when Mr Birt finished - in contrast to the desultory reception when he arrived at the podium. The speech was, however, less warmly received than Mr Tully's on Tuesday.
Mr Tully said later: 'I have no grandiose idea of leading an army of old soldiers into battle.' He said he was not opposed to change, but change must relate to broadcasting. 'You don't change the London Symphony Orchestra in the same way as you change Montague Burton or British Airways . . . The middle way is to look to the future but also to respect and love your past.'