Just days after his release in 1990, Nelson Mandela checked in for a South African Airways flight from Cape Town to Johannesburg.
When I spotted him I decided to upgrade myself, so I could try to get close. The plan was working: on board I was delighted to see that he and I were the only passengers in business class.
Half an hour into the two-hour flight I plucked up the courage, or the cheek, to walk over to him. "Good morning, Mr Mandela," I said, "I'm the journalist who wore that 'Free Mandela' T-shirt at your first press conference. My white South African colleagues hated that!"
He may well have felt unfairly ambushed, but he was surprisingly courteous and polite. "Sit down next to me," he said, and warmly shook my hand. "And just call me Madiba."
For the rest of the flight "Madiba" and I discussed only one subject – not his 27 years in jail, or his future tactics for negotiating with the still recalcitrant white-dominated government. We talked about boxing.
When I pulled out a photograph from my briefcase – of Mandela as a young boxer in the 1950s – his eyes (damaged by years of hewing salty rocks on Robben Island) lit up . "Oh yes," he enthused. "I remember that day very well. I didn't win!"
He had loved boxing, he said, because it relieved the strains of work as a young black lawyer operating in a profession that, in the 1950s, was almost entirely whites-only. Young Nelson saw boxing at a local Soweto club as a template for the world he dreamed of creating for all South Africans: a society where everyone was equal and treated on his or her merits.
"Boxing is egalitarian," Mandela told me, eyes transfixed by the picture. "When you're probing your opponent's strengths and weaknesses, you're not thinking about his colour or his social status. In the ring, rank, age, colour and wealth are irrelevant."
A very similar quote now appears on a plaque alongside a huge multi-dimensional statue, unveiled this year, of the great man, his clenched fists raised inside boxing gloves. Modelled on the same photograph, it towers in the street alongside the Johannesburg magistrates' court where in the bad old days the apartheid law enforcers would jail blacks for breaching pass laws that made them "temporary sojourners" in their own land.
In 1990 Mandela also considered boxing strategy to be the ideal training for what was to come: four tough years of tortuous negotiation with the country's white rulers. "It teaches you when and how to attack and to defend," he said. "And how to pace yourself over what could be a long contest."
Since that flight from Cape Town in 1990, Mandela from time to time would enlighten me about his sporting strategy: to use sport as a political tool, first to make white South Africans feel more willing to relinquish their monopoly of power, and then to build multi-racial national bonds in place of bitterness and resentment.
During his last weeks in prison, Mandela had authorised his African National Congress to launch the mass demonstrations and disruption that cut short Mike Gatting's England rebel cricket tour.
But by then, he had secretly approved clandestine contacts with the "racist" cricket authorities, aimed at forming multi-racial teams and rejecting government sports policies.
In the 1970s I had been a young white cricket umpire who had incurred the wrath of the white cricket establishment by "defecting" to the anti-apartheid non-white cricket leagues.
In an era of segregation, even sharing a dressing room or an after-match beer was illegal. Liaising secretly with the long-banned ANC, I was involved even then in a form of subversion: trying to bring whites and non-whites together in one cricket body, so undermining the very basis of "separate development".
Over a decade later, talks held in my London home and elsewhere were moving towards a potential deal, tacitly backed by Mandela from his jail cell. Hardline politicians and sports administrators on both extremes tried to block us.
But everything was superseded by President FW de Klerk's dramatic announcement on 2 February, 1990 that the white government was un-banning the ANC and was about to free Mandela.
The first major lifting of the blanket ban on international sporting contacts came when, late in 1991, Mandela supported sending the national cricket side, under Clive Rice, on a short visit to India. That was followed months later by an even more historic tour of the West Indies. Till then, neither India nor West Indies had ever played cricket against South Africa.
Another, much more important breakthrough for South African sport would be its readmission to the Olympic movement. Would Mandela support the idea that, even while there was no overall political settlement in racially-divided South Africa, the still white-ruled country could send a multi-racial team to the 1992 Olympic Games?
The idea of South Africa's flag, which had symbolised white control over the country, fluttering alongside those of its former enemies at the world's premier sporting event had been anathema to most in the anti-apartheid movement worldwide.
And indeed, Mandela faced strong dissatisfaction within his party over his bold policy of reconciliation or, as he called it, "nation-building", through sport. (That type of dissent carried on even after white rule was removed, as the film Invictus accurately portrays.)
Nevertheless, in 1991 Mandela and a handful of his party's leadership met a top-level delegation from the International Olympic Committee inside the terminal of a tiny airstrip in the picturesque Eastern Transvaal.
It was chosen because it was so remote and also because Mandela was enjoying a few days' rest on a private game-ranch nearby. I was privileged to be there and to film this otherwise secret meeting for later broadcast.
When a famous black athlete and IOC delegate, the American hurdler Ed Moses, tearfully embraced Mandela just before the ANC leader boarded the game-ranch's helicopter, I realised a deal was close. A multi-racial South African team could be heading to Barcelona the next year.
Even so, it was touch and go. Or not go. As political tensions in South Africa mounted in 1992, Mandela threatened to block the team's departure unless faster integration of previously segregated sports bodies took place, and the white regime's secret police stopped provoking political violence.
He got his way. Mandela was fêted at the Olympics as guest of honour, while President De Klerk was pointedly absent from the guest list.
When Mandela was inaugurated in 1994 as the country's first black president, I was in the VIP area – through a security lapse rather than by invitation. As he walked past, Madiba recognised me, smiled broadly, and said: "Hello Paul. Here I am. We're boxing clever. And we're winning – so far!"
Even as president, his interest in boxing showed no sign of waning. Mike Tyson gave him signed boxing gloves, which he promptly handed over to his daughter Zindzi – yes, she boxes too.
Madiba's unity-through-sport strategy came to full fruition in 1995. Rugby had been reviled by anti-apartheid activists for decades as the white man's game, the epitome of racial exclusion.
And more than a year into Mandela's official rule, only a small proportion of the top players were black. When South Africa hosted the World Cup, though, Mandela (against the wishes of many of the ANC leadership) chose to do the unthinkable – he donned a green-and-gold Springbok jersey (pictured), went onto the field and danced and hugged the no-longer-racist Springbok captain Francois Pienaar. They jointly lifted the trophy.
A couple of days later, amid national euphoria, Mandela and I filmed an interview in the sun-drenched garden of his Johannesburg home.
"Three years ago," he told me, "if South Africa had played the New Zealanders at rugby, I would have been cheering for the All Blacks."
Afterwards, as we packed away our cameras, Mandela lingered, put on his dark glasses, and threw me an imaginary rugby ball. "There you are, Paul. You see. Nation-building. It worked!"
Yes, Madiba, it did.