SAINTS pulled themselves off the canvas following an unconvincing first half to take the scalp of Challenge Cup winners Leeds.
Lance Hohaia’s coolly taken 74th minute drop goal proved to be the difference between the sides after Saints had initially failed to come to terms with being numerically superior.
The Rhinos had suffered the red carding of Joel Moon, who was given his marching orders for his challenge on Mark Percival – but seemed to cope well.
However Saints just about found enough to snatch the win to put them in the driving seat for the League Leaders’ Shield.
Saints took an early lead when Percival kicked a third minute penalty, but that was swiftly cancelled out by one from Kevin Sinfield.
Saints were guilty of some daft handling errors, which allowed Leeds to enjoy territorial advantage in the opening 40.
The game should have changed on 22 minutes when Leeds centre Joel Moon caught opposite number Percival high.
Both left the field, Percival was helped off in a groggy state, following Moon, who was shown the red card.
Leeds handled the situation better, nudging ahead when James Roby was penalised for holding down Jamie Peacock and Sinfield duly converted.
And then the Rhinos stretched that lead when Liam Sutcliffe skipped through some poor tackling from a cluster of player, not least from makeshift centre McCarthy-Scarsbrook, to touch down.
And when Lance Hohaia, back in after missing the last four weeks with a foot muscle injury, was penalised for stripping the ball Sinfield did not miss.
That gave Leeds a 12-2 interval lead – one they held pretty well at the start of the second half.
Saints were largely kept at bay, although Shannonn McDonnell was unlucky with his dash to the line.
It forced Saints into some pretty desperate often baffling tactics, like kicking on the third tackle, but all to no avail.
But two good back-to-back charges from Mose Masoe followed by a fine kick chase forced a Leeds drop out.
After piling forward, Hohaia dropped off a neat inside ball for McCarthy-Scarsbrook to power home from close range.
Although Jordan Turner missed the goal, Saints were back in it –and Leeds were beginning to show the first signs of hanging on.
Saints sensed it was do or die and a wonderful 40/20 from Turner gave them the position to pile on the pressure.
Three good drives in the middle were followed by a James Roby dart from dummy half – with the line parting for him to touch down.
Tomm Makinson tagged on the extras to equalise with ten minutes to play.
And with six minutes to play Hohaia used his big match nerve to settle it with a well-taken drop goal with Saints having the wherewithal to hold on.
Leeds: Hardaker; Briscoe, Watkins, Moon, Hall; Sinfield, Sutcliffe; Bailey, Aiton, Peacock, Jones-Buchanan, Ablett, Delaney. Subs: Leuluai, Ward, Achurch, Singleton.
Saints: McDonnell; Makinson, Percival, Jones, Dawson; Hohaia, Wellens; Amor, Roby, Walmsley, McCarthy-Scarsbrook, Laffranchi, Turner. Subs: Masoe, Soliola, Manu, Flanagan.