Call the competition what you like, broadcast it on whatever channel you wish, divvy the proceeds up by endless negotiation if you must – but whatever the make-up of future cross-border tournaments turns out to be, let the paying punter hope and pray it is replete with good old knockabout Anglo-Welsh rucks such as this.
It ended with Quins' third home defeat of the season, prompting their director of rugby Conor O'Shea to launch an uncharacteristic broadside at his players. "I'm furious," he said. "There were some individuals who gave everything like Mike Brown, Nick Easter and Chris Robshaw who kept coming, but it's not a game of touch and that's what it looked like during some of [the Scarlets'] tries."
Asked if this was the most disappointed he had been after a match in his three and a half years at the club, during which they were Premiership champions in 2012, O'Shea agreed it was. "We have to man up and take the flak that comes our way," he added.
With one semi-final appearance between them in the last 11 seasons, neither Harlequins nor the Scarlets has been a big hitter in the recent history of the Heineken Cup, the competition which has an uncertain future with the English and French clubs seeking more power and more cash for their participation. Currently both these teams are mid-table in their respective leagues, the Aviva Premiership and RaboDirect Pro 12. But with a plethora of Williamses running wild, a dash of controversy as the Scarlets' prop Samson Lee got away with a yellow card when his boot made contact with Danny Care's head in the second half, and a questionable call near the end by Quins' captain Robshaw, this was cracking entertainment.
Lee was said by the television match official to have not taken enough care when he trod on Harlequins' England scrum-half at a 44th-minute ruck, but not with sufficient recklessness to warrant a red card. Harlequins were attempting to narrow a 10-point half-time deficit at that stage. The one-man advantage they held while Lee was off did them little good, not least because the Scarlets' centre Scott Williams pushing on the flank of a scrum that earned Scarlets a penalty kicked by Rhys Priestland to extend their lead to 26-13.
Thereafter the sacking of the Stoop, painfully familiar of late, was completed with a try down the left wing by Jordan Williams – after Joe Marler had the ball ripped by Scott Williams – replied to for Quins by Mike Brown. Trailing by seven points with two minutesleft, and with another Scarlets prop Phil John binned for pulling down a maul, Quins and Robshaw contentiously chose a line-out over the scrum. At length the ball went long to Paul Sackey on the left wing and he put in a toe in touch under pressure from Liam Williams, the Scarlets' full-back.
The Welsh region will remember that two years ago they won away to Northampton in their opening group match but failed to qualify. And today's match between Clermont and Racing Metro will indicate the true and possibly daunting balance of power in Pool Four.
For now the Scarlets will revel in the tries they scored. The first after seven minutes was a handling extravaganza begun by the visitors' captain and Lions centre Jonathan Davies and taken on in an exchange between Priestland – making a case here to start for Wales next month – and Kristian Phillips before the scrum-half Rhodri Williams finished.
Two penalties by Priestland to one by Evans had Quins 13-3 down but heartened when Brown had his first try, taking Nick Easter's overhead pass after the No 8 had made the most of a bounce from Evans's cross-kick that foxed Liam Williams.
Just before the break Scarlets ripped Quins apart again, this time straight up the middle. Liam Williams caught a high ball and twisted his body to make a little ground before Scott Williams hared over the halfway line and never relented, throwing a couple of dummies on the way to a try converted by Priestland.
If the first-half tries showed Scarlets' prowess from long range, they might have been out of sight if they'd had the same success from the more obviously promising position of a five-metre scrum in the 28th minute. Instead an eventual overlap that needed a very quick take-and-give went unfinished.
Evans's drop goal was the curtain-raiser in a rousing second half, with Priestland and his Quins opposite number knocking over two more penalties each before Brown traced an unlikely arc into the right-hand corner with 72 minutes gone. Evans's conversion had Quins thinking of a draw. But Robshaw's line-out gamble did not come off.
Harlequins M Brown; T Williams, M Hopper (C Walker 65), B Botica, S Smith (P Sackey, 52); N Evans, D Care (K Dickson, 52); J Marler, R Buchanan (D Ward, 57), W Collier (K Sinckler 65), G Merrick (T Guest, 54), G Robson, M Fa'asavalu ,(L Wallace, 20), C Robshaw (capt), N Easter.
Scarlets L Williams; K Phillips (S Shingler, 23), J Davies (capt), S Williams, J Williams; R Priestland (G Maule, 70), R Williams (G Davies, 62); P John (R Evans, 70), E Phillips, S Lee (J Adriaanse, 53), J Ball (J Snyman, 62), G Earle, A Shingler (John, 80), J Barclay (Adriaanse, 47-53; C Price, 70), J Turnbull.
Referee J Lacey (Ireland).
Tries: Brown 2
Cons: Evans 2
Pens: Evans 3
Drop goal: Evans
Tries: R Williams, S Williams, J Williams
Cons: Priestland 3
Pens: Priestland 4