The West Yorkshire club had stunned Wigan Warriors last Friday but here they had no answer eventually to the ruthless nature of Justin Holbrook’s side who maintained their 100 per cent winning start to the campaign.
Huddersfield were competitive to start with and level 12-12 just before the break but then conceded a soft try to Mark Percival, the England centre who would crucially profit in similar fashion as his side took firm control in the second period.
Thereafter, Giants, who lost second-row Joe Wardle with a concussion and prop Matty English to a serious knee injury, were out-classed as Saints eased home with four unanswered tries to make it six wins from six this term.
In all fairness, the visitors did not really have to hit top gear as Huddersfield - still missing some key players - simply gifted them too much position.
Darnell McIntosh sailed a restart out dead, Akuila Uate spilled another kick near his own line to help set up Regan Grace’s score and Matt Frawley got caught on the last tackle denying Giants the chance to create some rare pressure of their own.
Granted, Jermaine McGillvary and Jordan Turner both had second half tries rightly ruled out but neither would have changed the contest here.
What did, arguably, was Percival’s second in the 54th minute.
Lachlan Coote, the stylish Australian full-back who excelled, produced a fine long kick out of dummy-half that sat perfectly behind Huddersfield’s goalline.
McGillvary did his utmost to escape but, under pressure trying to get rid, lost possession and saw Percival mop up.
Coote, who had earlier slotted a penalty illustrating the tightness of the contest, made it 24-12 and Holbrook’s side did not look back.
Huddersfield, who had drafted in youngsters Innes Senior and Sam Hewitt, saw Grace go over from Coote’s long ball as McGillvary rushed infield just after the hour.
Golden Boot winner Tommy Makinson then climbed high to palm down a kick for Dominique Peyroux to score and, after another drop-out was conceded, England star Jonny Lomax sliced over for their final try in the 72nd minute,
When England team-mate Luke Thompson barged over with alarming ease after just four minutes, Huddersfield fans may have feared the worst.
This was, let’s not forget, not an out-of-sorts Wigan team like the week before but a St Helens side that had won all five games so far.
However, Giants, who host Hull KR next Friday, quickly settled themselves and saw Frawley forced a drop-out with a smart kick.
Even when Uate was not so smart - letting a kick go dead but collecting the ball before it bounced on the other side of the line - to concede one themselves, they comfortably defended the set.
And, soon, they scored themselves.
James Roby, who made an unusual amount of errors last night, was penalised for interference on rival hooker Kruise Leeming and, from there, Giants moved the ball swiftly to McGillvary who produced a fine one-handed finish in the corner.
Lee Gaskell converted but Ukuma Ta’ai was quickly called upon to produce a cover tackle on Jonny Lomax, the England international spilling just as he seemed set to score Saints’ second try.
Giants could have forced some pressure themselves but Leeming’s kick was too heavy.
Instead, Roby, who had also earlier fumbled at dummy-half - perhaps this is what happens when the England star is rested as he was for last week’s win over London Broncos - rediscovered his usual sharpness.
He made a trademark break in midfield and only full-back Darnell McIntosh’s desperate flailing hand prevented it from reaching the onrushing Alex Walmsley for the try.
Still, they did cross in the next set, Roby again unpicking them too simply with an inside pass for Morgan Knowles.
Coote converted but when Giants forced Walmsley into spilling in the restart set, they immediately responded.
This time it was Jordan Turner, who won the 2014 Grand Final with Saints, who muscled over following sift hands down the right for Gaskell to level at 12-12.
English made a big impact off the bench, clearly looking to impress after being left out of the win at Wigan.
The young prop made some strong carries and some impressive hits before suffering his injury.
Ollie Roberts made a surging line break that resulted in nothing and when Hewitt fumbled after getting close to the line, Saints marched downfield off the back of another penalty.
Lomax dabbed a grubber in that Huddersfield should have dealt with but instead Percival sneaked in to score his first for a lead his side would never relinquish.
Huddersfield Giants: McIntosh; McGillvary, Turner, I Senior, Uate; Gaskell, Frawley; Ikahihifo, Leeming, Ta’ai, Joe Wardle, Mellor, Lawrence. Substitutes: Matagi, Roberts, Hewitt, English.
St Helens: Coote; Makinson, Naiqama, Percival, Grace; Lomax, Fages; Walmsley, Roby, Thompson, Taia, Peyroux, Knowles. Substitutes: Paulo, McCarthy=Scarsbrook,, Lees, Ashworth.Referee: Scott Mikalauskas (Leigh)