He said he was not ready, however, to take part in South Africa's first democratic elections next month.
Mr Mandela, the president of the African National Congress, had said before the meeting that he was prepared to go down on his knees before Chief Buthelezi to prevent bloodshed. Metaphorically, that was what Mr Mandela did.
Identifying Chief Buthelezi's complex personality as the cog around which the Inkatha machine turns, the ANC president mollified, praised and soothed, eventually persuading him to agree to what amounted to a peace treaty.
In a joint statement released after the all-day meeting at Durban's Royal Hotel, the two leaders said their two parties 'recognised the right of people to participate or not to participate in the forthcoming general elections'.
'After a constructive exchange of views,' the statement went on, 'the parties agreed to work together to ensure that canvassing for respective views should be able to take place without let or hindrance'.
This went to the very heart of the dilemma in Natal province, where there is fear that Inkatha, still refusing to take part in the elections, will mount a violent campaign against the ANC.
Amid substantial evidence that white right-wingers are training Inkatha Zulus to wage war against ANC Zulus - the latter being in the majority in Natal - the spectre has been raised time and again of civil war.
On paper at least, as satisfied ANC officials remarked yesterday evening, Inkatha is now committed to ceasing hostilities against people who campaign for the ANC.
Yesterday's statement went further, Chief Buthelezi having said that Inkatha would consider 'provisional registration' for the elections. International mediation was also raised as an option to resolve outstanding differences. Although no details were provided as to who the mediators might be, Chief Buthelezi pointed out that he and Mr Mandela had received a joint message of encouragement from Bill Clinton and John Major before yesterday's meeting.
Questioned, however, as to whether he had undergone a dramatic change of heart and had decided now to take part in the elections, Chief Buthelezi replied: 'Definitely not' and 'not at all'. If Inkatha decided provisionally to register, it was only in order to leave the door open in case the ANC made sufficient constitutional concessions in the coming weeks to persuade them to take part in the poll. This, in essence, meant granting Natal de facto sovereignty, as Chief Buthelezi made clear in an address he delivered at the start of the meeting yesterday morning.
Berating Mr Mandela for having engaged in 'farce' with his 'so- called concessions' 10 days ago, he defined his chief demand as 'Zulu sovereignty'. The alternative - even if most Zulus do not share his wish - was 'disaster' and 'a potent mix for increased violence'.
Not long into the meeting, however, Chief Buthelezi and Mr Mandela withdrew from their delegations and disappeared for a private exchange in an upstairs hotel room. When they re-emerged 45 minutes later they were smiling and holding hands. In fact, they held hands for two minutes before the cameras and then strolled down a 30-yard corridor, still holding hands.
Back inside the chamber with the delegations, Mr Mandela, according to an ANC insider, delivered a 20-minute eulogy of the Inkatha leaders. 'Buthelezi was almost reduced to tears,' the source said.
When the two leaders appeared before the cameras again at the evening press conference, the smiles remained as broad as they had been in the morning. Mr Mandela spoke of 'my friend Chief Buthelezi'; 'in spite of all our political differences we are very close friends,' he said; the meeting had been 'harmonious', 'fruitful', 'unforgettable'.
Chief Buthelezi began the press conference in slightly less generous mood. But by the end he said the encounter had been characterised by 'friendship and love'.