Paul Anderson’s side were rightly aggrieved; Joe Greenwood seemed to knock the ball clear from Huddersfield’s Luke Robinson when Saints won possession for the crucial play.
That said, the Giants coach will also point at some unusually soft defence from his side to allow the hosts a strong foothold in another absorbing game after the previous evening’s epic between Wigan Warriors and Leeds Rhinos.
And the visitors were also left to rue some early profligacy in the first period.
Crucially, though, former St Helens scrum-half Jamie Ellis also missed the vital conversion attempt of Aaron Murphy’s 72nd-minute try that had levelled the contest at 34-34.
It was the scrum-half’s only miscue of the evening but one, given his earlier accuracy from wide out, he would have expected to convert.
It meant that when St Helens’ Mark Percival then blazed the restart straight out into touch, captain Danny Brough – Huddersifeld’s usual goalkicker who had, up to this point, rested his left leg from goalkicking duties after picking up an injury late on against Hull KR last Sunday – opted to take on the responsibility himself from halfway.
It was a bold call but few would argue with one of Super League’s most prolific marksmen especially given Ellis’s mind might not have been in the right place.
This time, however, Brough’s 50m shot was just short and just wide so Saints – who had taken a two-score lead for the first time at 34-24 when Percival crossed for his second try on 64 minutes – breathed again and held on to inflict only the Fartowners’ second league defeat in 11 games.
Adam Quinlan proved lucky number seven for the home side, the Australian who only arrived in the UK on Monday, becoming the seventh player to operate in Saints’ jinxed full-back role this season but duly scoring a dream debut first-half hat-trick to leave them 18-12 ahead at the break.
Yet Huddersfield created three clear try-scoring opportunities inside the opening 10 minutes only to somehow convert none.
They could have been out of sight but Jack Hughes botched his break by throwing an awful pass to full-back Scott Grix - returning having lost his place to tyro Jared Simpson for the last four games - after just 50 seconds and Joe Wardle was then dragged down at the last by Travis Burns having rounded Quinlan all too easily.
Wardle’s next surge saw Jermaine McGillvary eventually go over in the opposite corner from Leroy Cudjoe’s clever flick pass only to be ruled out by the officials for a foot in touch.
A threatening Hughes was shot down next by a timely Walsh tackle and, so, it was almost inevitable that Saints – who looked badly out of sorts having also been thrashed by Leeds last week – would score with their first attack, James Roby’s dinked grubber bouncing back fortuitously off Grix for Quinlan to get the first of his treble on 16 minutes.
Walsh slotted the first of his five conversions but the visitors did finally make their own breakthrough via Hughes in the 22nd minute when the Wigan loanee stretched out of a tackle after Craig Huby had barrelled close.
Ellis converted but Keiron Cunnigham’s men were able to capitalise on some wretched Huddersfield defence on the half-hour when the visitors failed three times to shut down their opponents before Quinlan picked up a hopeful offload to grab his second try. Thankfully for Huddersfield, Josh Jones and Adam Swift contrived to let the restart find touch and Grix grasped the opportunity, his dummy followed by an unexpected grubber, leaving Saints rooted and McGillvary crossing for the winger’s 12th try this year.
Ellis levelled at 12-12 but there was more frustration as Quinlan finished off his hat-trick, Roby getting on the outside of Nathan Mason – the 21-year prop playing his first Super League game since debuting in 2013 – and furnishing the supporting ex-Parramatta Eels man.
Huddersfield, now clinging onto fourth spot, bombed another try before half-time as Michael Lawrence dallied but Cudjoe scored his 99th career try on 45 minutes only for Percival to embarrass some woeful defence once more.
McGillvary added his second after some brilliant handling from the excellent Hughes and Grix but yet again Saints responded, Greenwood benefitting from Roby’s assist.
When Ellis knocked on, Percival looked to have taken decisive control for the hosts but there was more drama still to come.
Ukuma Ta’ai stole possession from Roby who was then penalised for dissent handing position for Eorl Crabtree to keep Huddersfield in it in the 70th minute. Murphy then stormed over off Ellis’s well-timed pass.
But Ellis missed the conversion, Brough was off target, too, and Walsh – whose drop goal sent Giants out of the Challenge Cup last season – stepped up to leave Saints just a point behind leaders Leeds.
St Helens: Quinlan; Dawson, Percival, Turner, Swift; Burns, Walsh; Amor, Roby, Masoe, McCarthy-Scarsbrook, Greenwood, Jones. Substitutes: Walmsley, Flanagan, Richards, Savelio.
Huddersfield Giants: Grix; McGillvary, Cudjoe, Murphy, Broughton; Brough, Ellis; Crabtree, Robinson, Huby, Wardle, Hughes, Ta’ai. Substitutes: Lawrence, Kopczak, Wood, Mason.
Referee: B Thaler (Wakefield).