Immediately the Edinburgh-born solicitor and businessman from Wiltshire promised the dawn of a new era, to reinvigorate a club which had lost its place as one of the top teams in the country.
Protracted negotiations with Kenny Waugh had dragged on over the summer before Duff finally persuaded the then chairman to part with his 406,000 shares at a cost of more than 700,000, becoming Hibs' fifth owner since the war.
It was a dream move for Duff, unknown in the city of his birth but a lifelong supporter, having grown up in Bonnington Road and Crewe Road North and becoming a pupil at Trinity Academy.
His first step was to appoint his brother-in-law Jim Gray, pictured, as the club's first full-time managing director and, in the following 12 months, the pair pulled Hibs out of relegation trouble. Duff had grandiose plans for Hibs, backing up his promises by immediately sanctioning a 100,000 bid to buy Neil Orr from West Ham. Andy Watson arrived a few days later, Andy Goram following for a club record fee of 325,000 two months further on. But even the signing of Goram was put in the shade somewhat as Hibs pulled off a major coup in snapping up former Aberdeen, Spurs and Barcelona striker Steve Archibald on the eve of the following season despite stiff competition from Liverpool.
Attendances soared as Hibs challenged for their first European place in 11 years and reached the semi-finals of the Scottish Cup, the arrival of Keith Houchen from Coventry City for 300,000 yet another indication of Duff's determination to return Hibs to the top of Scottish football, as was the capture of Brian Hamilton from St Mirren in 1989, the 300,000 deal to bring in Paul Wright from Queens Park Rangers and a further 175,000 as Hibs fought off Liverpool to land Mark McGraw from Morton.
In addition, John Collins was signed for another two years at a time when everyone thought he was on the point of leaving.
Supporters, of course, pay far more attention to what is happening on the pitch than boardroom activity but little could they have thought that barely three years after welcoming Duff to the helm they'd find their club under threat from Hearts chairman Wallace Mercer.
If Mercer's takeover bid shook Scottish football to its core, it also prompted a close examination of how Hibs had become so vulnerable to such a move, debts having soared from 882,000 at the end of 1988 to 4.5million only days before the Tynecastle supremo launched his audacious bid which, if successful, would have wiped the Easter Road club off the map.
Even before Mercer's 6.2m bid, boardroom troubles at Hibs were coming to a head, prompting many unanswered questions surrounding Duff's purchase, management and chairmanship of the club, the feeling being he hadn't been "totally up-front" with his fellow directors.
Among the greatest worries was the position and intentions of David Rowland, a Monaco-based property developer with a chequered track record in the City.
It was Rowland who loaned Duff the money he needed to buy Hibs, acquiring a 29.9 per cent stake when Edinburgh Hibernian plc successfully floated on the Stock Exchange Third Market, raising a net 1.6m in October 1988, the first in Scotland to involve a football club.
The ambitions, however, didn't rest solely on Hibs' fortunes, the newly-floated company paying 1m for a pub in Exeter in November that year and the following month buying a Devon sports club for 400,000.
In February 1989, Duff announced a further share issue to finance the 5.6m purchase of Avon Inns, a chain of 15 pubs and restaurants in the West Country which had been recently bought by Rowland's company Inoco plc when in receivership.
Shareholders among the fans were critical of the club's financial position while Duff was also facing an impatient board made up of himself, Gray, Allan Munro, Rowland and his first wife Sheila, and a Rowland associate Jeremy James.
Tom O'Malley, a leading figure in the Hands off Hibs campaign which fought Mercer's advances and who later became chairman of the football club, said: "When you look back at the structure of things with the football club just part of the plc and all those shadowy figures in the south of France, I suppose we were ripe for a takeover of one kind or another."
While Duff was effectively under pressure to produce a deal, a transfer fee windfall, or a rescue package by the end of the company's financial year on July 31, the real threat emerged from outside the club.
A financier Ronnie McNeill became aware that Rowland had no intention of long-term investment in Hibs and wanted to offload his shareholding, having already sold 15 per cent which were in his own name, pocketing 1.5m before building Inoco's stake back up to almost 30 per cent when the price was languishing, at one time dropping to just 17p. By selling out now to Mercer at 40p, the initial offer price, he would have made another 1.8m if the bid had succeeded in addition to the profit made on the 5.6m received by Inoco from Hibs for Avon Inns.
McNeill became the crucial link between Mercer and Rowland, although it is believed his original intention was to buy a stake in Hibs for himself before being sidelined as the Hearts chief secured an "irrevocable" undertaking from Rowland to sell his shares, setting the scene for a hostile bid.
Exactly how much Duff knew of what was going on behind the scenes, or if, indeed, he was aware Mercer was the predator, has never been ascertained – and is unlikely now, 20 years on, to be revealed – but the upshot remained the same, shock and dismay at the disclosure it was Mercer, the owner of Hearts, who wanted to take over Hibs.
Three days after Mercer went public, the Hibs board, their hands tied by Stock Market rules and unable to voice, at least in public, their opposition, met again and by 4-2 rejected Mercer's offer, the two dissenters were David Rowland and James.
In the end, it was Duff's determination not to sell his 11 per cent stake in Hibs to Mercer which proved crucial in preventing the Tynecastle owner from gaining control of the 76.1 per cent holding he needed to succeed in taking over his Capital rivals.
Days after Mercer admitted defeat, Duff resigned as chairman, Alister Dow taking the hotseat at the head of a new board including Tom Farmer and his associate Tom Harrison.
Ironically, the words Duff had uttered shortly after taking over at Easter Road had become prophetic. "There will be a revolution," he had said, "but it won't happen overnight.
"It could take five years but I would like to do it in three."
In fact, the story of David Duff, chairman of Hibs, lasted a month short of three years: appointed on 24 August, 1987, resigned 27 July, 1990.
But, sadly, it wasn't the last Hibs fans had heard of Duff as the flamboyant executive who enjoyed expensive cars, foreign travel and meals in the best restaurants, later found himself in court in England, convicted of swindling building societies out of hundreds of thousands of pounds and jailed for two years.
Was this the Edinburgh team to topple Celtic and Rangers?
WALLACE MERCER'S big idea was for an "Edinburgh United" – so what would have been the Capital select made up of stars from Hearts and Hibs at the time of his takeover bid?
The first requirement is to employ a system to suit the squad, and that would mean playing with three central defenders – Craig Levein, Dave McPherson and Gordon Hunter, operating in front of Andy Goram.
In midfield two wide players with the ability to defend and attack; Paul Kane to operate on the right and Tosh McKinlay on the left with Gary Mackay and John Collins operating between them.
That leaves three forwards, John Robertson and two others, John Colquhoun and Paul Wright.
A team that never played together, but enough to start a few more arguments ...