With Hearn at the promotional helm of a contest that will bring together Ray "Barney Rubble" Barneveld, the British Darts Organisation title holder, and Phil "the Power" Taylor, the seven-times winner of the Professional Darts Council title, underselling was never a realistic concern.
"We're going to have 3,000 people hanging from the rafters, all supporting one or the other. This is not a match for neutrals. It'll be like England against Germany at football."
More like England against the Netherlands in fact. Barneveld, a postman from The Hague, is a rather bigger sporting celebrity in his native land than Taylor is in Britain and has a band of followers who loyally sport orange wigs or Flintstone outfits wherever they go in his support. On this occasion the rafters that they will be endangering are those at the Wembley Conference Centre on 7 November.
More important than the antics of the crowd at Wembley, though, is the rather larger audience expected as darts receives its first, and much needed, exposure throughout the ITV network since the 1980s. Crucially, the broadcast has not been shuffled into the small hours but will be shown live at the slightly closer to prime time - or rather high-tea time - of 4pm on a Sunday.
The match, which will be the best of 25 games, will offer the largest purse ever for a darts contest: pounds 60,000 to the winner and pounds 40,000 to the loser.
As Hearn, almost convincingly, said yesterday: "The money's incidental. Ultimately, this event had to happen. Like in boxing, when you get two guys this good then you have to find out."
Hearn, better known for his boxing promotions, could not stop himself from slipping in a few more analogies with the noble art. "It"ll be like Leonard v Duran, Eubank v Benn." Mercifully, there will be no weigh-in for Barneveld v Taylor.
"On the undercard we've got Rod Harrington [the world's top-rated player], who I nearly said will fight, I mean will play, Co Stompe [the Dutch No 2]. Then comes the big one, the entry of the gladiators. This is going to be a titanic struggle."
The imagery was close enough to being appropriate as the announcement of the contest took place on the World War II cruiser HMS Belfast, moored beside London Bridge. Her powerful armoury stayed silent yesterday and the two big guns left most of the talking to Hearn.
"The English and Dutch fans will be segregated at Wembley, not because we're expecting any trouble, but because it'll look better on telly. Orange on one side, Union Jacks on the other.
"This is an emotional and historic moment for the world of darts."