Just like the Wembley run which made them household names, Wigan’s Good Friday record came to a halt at ‘eight in a row’.
Five of Wigan’s backs were still in school the last time Saints won a Good Friday derby in 2009.
But despite a gutsy late finish, Shaun Wane’s outfit couldn’t extend their proud run in this marquee fixture to a ninth year.
Willie Isa’s try - converted by George Williams - put them into a 14-12 lead to set up a nervy final 10 minutes.
Danny Richardson’s controversial penalty levelled the scores before Regan Grace’s try, converted by the former, opened up a six-point gap.
Richardson then gave Saints some breathing space with a drop-goal. Joel Tomkins’ surging solo effort cut the margin to three points but it was the final play of an aborbing contest.
As a spectacle, the match lived up expectations as Saints moved four points clear at the top of the ladder.
Wigan made a bright start and took a 2-0 lead, but Saints gradually took a grip of the game and led 12-2 at the break - only for the visitors to come back strong.
Sam Tomkins’ absence to a sickness bug saw Morgan Escare drafted back in earlier than expected from a virus. Josh Woods, a young halfback who played twice last year, took a bench spot.
Saints had their 80s favourite Mal Meninga, the Australia coach, among the 18,000-capacity crowd which included around 4,000 Warriors fans.
“Looking forward to a fantastic game,” he said, when introduced to the fans. “Go Saints.”
He got his wish, in that Saints won, and if some of early spells were flat, they certainly livened up the longer the game went on.
Wigan were forced to defend for large parts of the opening half, it drained their energy and their attack suffered.
They started well, and Escare kicked them into a 2-0 lead after referee Robert Hicks penalised Saints for stripping the ball from Ben Flower’s grasp. They remained on the front-foot, for a spell.
Richardson’ penalty kick for touch missiled straight into the grateful arms of Joe Burgess, and moments later the video referee was called on to rule out a Burgess effort.
At the other end, left winger Burgess and his centre Oliver Gildart did a good job defusing the kicks aimed their way - the latter also pulled off a stinging tackle on Ben Barba. But the Australian full-back soon made his mark, taking Luke Thompson’s offload, zipped through an inviting gap and left a stranded Escare flapping. Richardson’s conversion put the hosts 6-2 ahead.
Hicks’ whistle frequently interrupted the action and Wigan’s defence continued to repel Saints’ wave of attacks. That was until just before half-time, when their line eventually creaked when Zeb Taia thundered over. Richardson’s goal made it 12-2.
There was a sense Wigan would need to score early from the restart to give themselves hope.
And Tomkins duly obliged, charging over from Williams’ inside pass in the 46th minute which - with Escare’s conversion - reeled in Saints’ lead to just four points.
Saints, though, appeared far more dangerous and it needed some huge defensive efforts from Escare and Tom Davies to fend them off.
Escare left the action concussed, and Wane brought back big-guns Flower, Thomas Leuluai and Sean O’Loughlin as the game approached the final quarter.
Wigan improved. They got back into the grind of the contest, cutting their errors and completing their sets. And with O’Loughlin steering the ship, they locked the scores when Willie Isa - right backrower-turned-left centre - scooped up a bounced pass and crashed over.
With Escare off, Williams stepped up and nailed the conversion to put Wigan 14-12 ahead and set up a nerve-shredding final 13 minutes.
Richardson locked the scores up after O’Loughlin was adjudged to have stolen the ball - replays suggested it was a harsh call, though the game was littered with seemingly-soft penalty decisions. Powell pushed a drop-goal wide before Saints swept down field, swung the ball to the left edge and Grace dived over. Richardson’s sideline conversion left Wigan trailing by six points with three minutes to go.
Richardson secured the two points before Tomkins’ late, impressive effort.
St Helens: Barba; Makinson, Morgan, Percival, Grace; Lomax, Richardson; Amor, Roby, Thompson, Peyroux, Taia, Wilkin. Subs: Fages, McCarthy-Scarsbrook, Douglas, Knowles.
Wigan: Escare; Davies, Bateman, Gildart, Burgess; Williams, Powell; Clubb, Leuluai, Flower, Isa, Farrell, O’Loughlin. Subs: J Tomkins, Sutton Tautai, Woods.
Referee: R Hicks