And for no one does it have more significance than for a player who has moved from one side to another. So Bobby Goulding, playing for Saints against his original club for the first time, does not even attempt to classify it as "just another game".
"I've played for Wigan against Saints, but I never realised how big a game it was for the spectators until I came to St Helens," he said.
Those spectators, he has noticed, are still talking about Saints' remarkable 41-6 victory in the equivalent match two years ago. "But that is ancient history to the players," he said. "Half of us weren't even here."
Goulding has fitted so snugly into the scrum-half's role at Knowsley Road that it requires as big an effort to remember that he only arrived this summer as it does to bear in mind that, despite being at his fourth professional club, he is still only 22.
He was only a teenager, and, by his own admission, a rather immature one, when he left Wigan, despairing of forcing his way past Andy Gregory and Shaun Edwards into a regular position at scrum-half.
Edwards dogs his footsteps still, the pair of them contesting the Great Britain No 7 shirt and now meeting head-to-head in the most pivotal domestic match of the season so far.
"It's a rivalry that will probably go on for many years to come, but you can't take personal rivalries into the game without affecting your own play.
"Nor do I feel that I've anything to prove to Wigan any more. They know what I can do. At the time, I felt I had to leave and I've no regrets about leaving."
His career since has been chequered to say the least, with spells at Leeds and Widnes separating his involvement with Monday's two combatants, but Goulding has looked at home since first pulling on a Saints shirt.
Apart from a dip in confidence after the disappointment of defeat in the Ashes series, Goulding has been an inspirational figure in a Saints side extensively rebuilt over the last 12 months.
The burgeoning promise of Steve Prescott and the rapid assimilation into league of Scott Gibbs and Apollo Perelini has given them a new look since they last met Wigan. They have re-discovered the invigorating style that has always characterised them at their best, but Goulding knows that the real test will come over the next two weeks.
On top of the Boxing Day derby, Saints have a Regal Trophy quarter-final against Wigan at Central Park on 8 January.
"If we want to win things this season, these are the matches we have to take," he said. "The boys are really looking forward to both of them. Contrary to what you might imagine, everyone looks forward to playing Wigan.
"The new interpretation of the rules suits us great, because the fittest side will always win.
"We've done a lot of work over the summer with Eric Hughes and it showed in the last 20 minutes against Batley in midweek, even though they were the better side for an hour. It will work in our favour against Wigan."
Even allowing for the warm glow of collective folk memory from two years ago, that does not indicate any lessening of the respect commanded by the men from across the East Lancashire Road.
"They are still a champion side," Goulding said. "They aren't affected by losing key players like they have done this year, because they just go out and buy some more."
It may be that the major stumbling block for the rest of this season, however, is a player they sold.