Should the home club avoid defeat, what has always been geographically the closest rivalry in Scottish football will become, next season, the biggest of the country's derbies for the first time.
There may be a late challenge from the capital, of course, if Hearts manage to maintain the death grip from which Hibs have so far looked too weak to break free, but those encounters will be diminished by taking place in a lower division.
From up north, too, where the Highland derby, marvelously dubbed "El Kessocko", has become increasingly intense in the two years since Ross County joined Inverness Caledonian Thistle in the top flight, an alternative case could be made, but that fixture is all rather new.
Even in Glasgow some would contend that the combined attendance at Celtic v Partick Thistle encounters will make that pre-eminent, but it can hardly be considered the Glasgow derby.
That Dens Park is sold out this afternoon offers a reminder of the depth of affection still felt for the city's oldest senior club and the implications for meetings with their neighbours.
As Rangers seek to complete their clamber up the leagues and Hearts to regroup, so the potential return of the derby between two clubs who sit a couple of hundred yards apart on Tannadice Street, can bring a welcome extra dimension to the top division.
Facing a Dumbarton side with nothing but pride to play for, the significance for Dundee should be enough in itself to secure a win.
Yet Paul Hartley, who took charge mid-season following another bizarre Dens crisis that ended in them parting company with their manager as the team sat joint top of the table, is not alone in registering concern.
"Don't play the occasion, play the game," he warned his men this week. "It will be a fantastic occasion, but we can't get caught up in that."
Dundee's manager also observed that: "As a player I always felt comfortable and confident in these situations and as a manager I feel good too."
He will surely understand that supporters old enough to have been around when the club last won a major trophy have less reason to feel relaxed on occasions such as this.
It is chastening to think that a celebratory dinner in Dundee in December marked the 40th anniversary of the club's last major trophy win, back around the time that my school-mates and I used to scramble under turnstiles. Even so, European nights, sitting on the pitch-side wall, buying pehs, Bovril and Tunnock's wafers from the passing trolley, linger fondly in the memory.
Contemplating what has happened in between it also seems apt that today's opportunity arises at the end of the first season of the Scottish Premiership. The name change may not have been terribly significant in itself, but Dundee supporters have no reason to think of the words "Premier Division" with any affection.
It was at the end of that competition's first season that everything changed in Dundee football.
The club's failure to retain the services of Jim McLean, allowing him to pop down the road to become Jerry Kerr's successor in 1971, is often cited as a seminal moment, yet it is intriguing to wonder what might have been had one point either way changed hands in the first SPL season back in 1975/76.
Would there ever have been a 'New Firm' had Aberdeen or Dundee United, who both avoided relegation on goal difference at Dundee's expense that season, gone down with St Johnstone?
Would 'Wee Jim' - already five years into the job without major success - have become the dominant figure in city football had United gone down? Indeed, given his 'previous' with St Mirren, would we have heard any more of Fergie had Aberdeen suffered the drop?
It was, though, Dundee that did so. The club that had produced one of Scottish football's greatest teams in the previous decade and was still considered the city's senior side through the early 70s, never really recovered.
Even setting aside the off-pitch horrors involving all sorts of foolish and dodgy manoeuvrings, questionable 'celebrity' signings and consequent spells in administration, the greatest pain has been inflicted in the interim by United as they have revelled in gaining the ascendancy.
Among many chastening days for those clad in dark blue, the low point surely came in 1980 when, during an unbeaten 13-match run in derbies, United visited Dens Park for the League Cup final and, with the ground able to accommodate more than 24,000 in those days, delivered a 3-0 thrashing.
That they were retaining the trophy, after winning it at Dens against Aberdeen the previous year, was bad enough but it paled in comparison to when they clinched their only national title win by beating Dundee on their own ground again three years later, results which only added to the agony experienced by the blue half of the city during that period.
Since United's record unbeaten run ended in 1983 some 77 derbies have produced just 19 wins for Dundee yet, if only for one season and in spite of the pain that may result, the prospect of featuring in Scotland's biggest derby match is still a tantalising one for those who will be jammed into Dens today.
That said, such is the history of these past four decades, few of them will be taking anything for granted.