Valkyrie made most of the early running, with Izzy Brennan’s shrewdly-placed kicks repeatedly putting the Saints defence under pressure, but they were unable to take advantage and fell behind after 10 minutes.
Losing possession just inside their own half, the defending champions were punished as Paige Travis picked out Burke, who motored down the left wing to maintain her record of scoring in every meeting with Valkyrie this season.
Owen struck back, pouncing to cross from close range after Saints fumbled another Brennan kick and the conversion edged Valkyrie in front, only for Rhiannon Marshall to spill another good opportunity close to the line soon afterwards.
St Helens found more rhythm as half-time approached and overturned the deficit to lead 8-6 at the break, with Gaskin – in her final game before retirement – nailing two kicks in quick succession after penalties against Gentles.
Yet the lead changed hands again just after the turnaround as Marshall’s kick bamboozled two Saints players and Owen grabbed the loose ball, feeding Partington who did superbly to stay inside the line and force her way over in the corner.
Georgie Hetherington’s incisive run, scything deep into Saints territory, then set up a chance for Gentles to touch down under the posts – and, despite an on-field decision to rule out the try, it was overturned by video referee Ben Thaler.
With their treble hopes fast disappearing, Saints stormed forward but they were repelled by a tenacious Valkyrie defence, with Carrie Roberts producing a try-saving tackle to foil Burke and Hetherington holding up Chantelle Crowl over the line.
Crowl then conceded a penalty for a high challenge but, although Brennan squandered the chance to earn her side additional breathing space by miscuing the kick, Valkyrie were not to be denied.
