Paul Sculthorpe staked his claim for a Wembley place by playing the full 80 minutes at the Galpharm Stadium.
The former Great Britain captain put in his longest stint of an injury-ravaged season to show that he is over his latest problem – a niggling hamstring – and ready to face Hull in Saturday's Challenge Cup final.
"Wild horses couldn't stop him making himself available for selection," said his coach, Daniel Anderson. "I haven't made my mind up yet but Paul deserves the chance to play in a big match at the end of his last season with the club."
Nick Fozzard, here in his third match back after a serious knee injury, could now be needed as a replacement for Jason Cayless, who damaged knee ligaments early in this game. Kyle Eastmond, who contributed 18 points from two tries and five goals, also made a case for a cup final place.
Saints made an uncertain start, falling behind when Eorl Crabtree caught them out with a kick over the defence which paved the way for Stuart Jones to score against his former club.
Saints will hope they did not use up any of their Wembley luck in the way they came back. After Kieron Cunningham's equalising try, the next two both came from Sean Long running at the defence on the last tackle and both seemed to involve a knock-on before Willie Talau and Eastmond scored.
Two minutes after half-time Luke Robinson put up a high kick, Shane Elford leapt to palm it back and Paul Whaturia went in for a Huddersfield try. The same combination featured 10 minutes later when Elford hacked on a loose ball spilled by Ade Gardner and Whaturia scored his second try.
Chris Thorman's conversion made for a two-point lead, but Saints pulled away again when Sculthorpe took a pass and released it in the same movement for Chris Flannery to score.
A loose ball scooped up by Dean McGilvray for a 40-metre try made sure Saints will go to Wembley with their winning run intact. Eastmond took his kicking total to five goals as well as scoring a second try. Danny Kirmond scored a sparkling solo effort for the Giants.
Huddersfield: Hodgson; Aspinwall, Brown, Whaturia, Elford; Thorman, Robinson; Crabtree, Hudson, Mason, Jones, Lolesi, Wild. Substitutes used: Griffin, Faiumu, Raleigh, Kirmond.
St Helens: Eastmond; Gardner, Gilmour, Talau, McGilvray; Wheeler, Long; Fozzard, Cunningham, Cayless, Flannery, Hargreaves, Sculthorpe. Substitutes used: Meli, Graham, Clough, Thompson.
Referee: B Thaler (Wakefield).Reuse content