Borderline decisions from video referee Ian Smith, crucial try-saving tackles and a rip-roaring last 40 minutes combined to leave both sets of players and their respective spectators drained when the final hooter sounded.
It was also sweet music
to every finger-nail biting Saints' fan in the stadium and watching on TV but the Last Post for a brave and gallant Wigan outfit and their success-starved followers.
A night of high drama and tension kept the supporters on tenterhooks from start to finish and in truth it was a pity there had to be a loser but in the sporting world agony and ecstasy go hand-in-glove, leaving the 2006 trophy winner on cloud nine as they head for the ultimate showdown with defending champions Leeds Rhinos and the Warriors ruing three successive defeat in the semi-final of the competition.
Saints have played much better and expansive football this season but it's a long time since I've seen them produce an 80 minute display free of any major handling errors and at the end of the day ruthless efficiency, rather than anything spectacular, tipped the balance their way.
In essence, though, it was a great all-round team performance with the hosts' second-half defending outstanding as Wigan launched a do-or-die bid to snatch their first victory on enemy soil since 2003.
Saints' boss Mick Potter said:"I thought we produced a really good performance against a determined team who put us under pressure, particularly in the second half.
"The game could have gone either way but as far as we are concerned it's just great that we are going back to Old Trafford and hopefully this time the result will go our way."
His Wigan counterpart, Brian Noble, who revealed he was leaving the club for pastures new at the end of the season, said: "I am absolutely gutted and devastated for the players because they deserved more than they got out of the game
"It was a fabulous tie but I don't think the rugby Gods were on our side tonight."
Saints certainly didn't need divine intervention to register their first points - a quality second minute try which shook Wigan rigid.
Diminutive centre Kyle Eastmond produced an electrifying burst down the left, sweeping past one leadened-footed defender and then ducking under the challenge of two others before setting up the highly impressive Francis Meli for his 16th try of the season.
But rather than set the game alight, it signalled the start of a dour battle for supremacy among the forwards, neither willing to chance their arm and clear cut openings few and far between.
Pat Richards thought he had restored at least parity after nine minutes, only to be smashed into touch by a brilliant last-ditch Sean Long tackle, before the visitors finally posted their first points after 24 minute.
A towering Sam Tomkins kick caused confusion in the Saints' defence after team-mate Richards failed to gather possession - the ball going between his arms - and then bouncing kindly to enable the supporting George Carmont to stroll in.
Richards goaled but Saints were convinced they had regained the lead when Lee Gilmour, playing his final home game for the club before joining Huddersfield Giants, sent Meli squeezing over in the left-hand, only for the video referee to rule he had one foot in touch.
It was a highly controversial call but five minutes later he redressed the balance - insisting that Long had slid over the line when it appeared he had been a fraction short of the whitewash.
Eastmond's goal gave Saints a 10-6 interval advantage and in a blistering opening to the second half they increased their lead to 14-6 in the 50th minute, Long's raking pass seized on by Meli who glided over in the left-hand corner.
Wigan's Andy Coley was placed on report for a high tackle on Lee Gilmour as the decibel level increased and it moved up a further notch or two as a sensational Richards' try in the 70th minute rekindled Wigan's hopes of victory.
The wingman scorched down the left touchline before opting to hack on as both Paul Wellens and Leon Pryce closed in but was able to twist and turn his way over the line to score and reduce the deficit to only four points.
It set the scene for a frenetic finale and it took a magnificent Sean Long tackle on Joel Tomkins to deny Wigan a further try and possibly a place in the Grand Final.
Earlier in the day the scrum half, who is moving to Hull FC at the end of the season, had spent a couple of hours signing copies of his autobiography ... just a pity the final chapter of his Saints' career won't be included.
Teams: Saints: Wellens, Gardner, Gidley, Eastmond, Meli, Pryce, Long, Graham, Cunningham, Puletua, Flannery, Wilkin, Gilmour.
Wigan Warriors: Phelps, Roberts, Gleeson, Carmont, Richards, Tomkins (S.), Leuluai, Coley, Riddell, Prescott, Tomkins (J.), Hansen, O'Loughlin.
Subs: Fielden, Palea'aesina, Mossop, Flanagan.
Referee: Steve Ganson (Haydock).
Attendance: 13,087.
