Saints hold on against Vikings
St Helens survived a rousing Widnes fightback to earn a 40-38 victory and seal a place in the fifth round of the Challenge Cup.
Saints looked set for a comfortable victory when they led 40-22 before Kurt Haggerty went over for Widnes.
Then Saints hooker James Roby was sin-binned for a professional foul and Widnes hit back with three late tries from Hep Cahill, Patrick Ah Van and Lloyd White.
Widnes would have drawn had Ah Van's attempted conversion to his own try not hit the post four minutes from time.
Widnes knew they needed to put their league form to one side to follow Featherstone, who beat Castleford, in pulling off another fourth-round shock.
Widnes are propping up Super League with only two wins in 11 matches back in the big-time - a surprise victory over under-strength Wigan followed by a home triumph against London.
The Vikings conceded 84 points in Easter defeats by Warrington and Bradford and completed a miserable week by releasing ex-St Helens star Scott Moore.
Saints handed a debut to 19-year-old winger Adam Swift in preference to Jamie Foster with Ade Gardner ruled out with a knee injury.
Tony Puletua was also missing alongside Jon Wilkin for Saints who welcomed back Jonny Lomax from a broken finger.
Widnes stunned Saints by sweeping into an early lead when Jack Owens linked up smartly to send Ah Van over in the corner after only three minutes.
But Saints hit back immediately when Widnes forward Haggerty's loose pass was snapped up by Anthony Laffranchi with Josh Jones touching down for his first try for the club to make it 4-4.
Roby was the instigator of Paul Wellens' try after 14 minutes with his darting run from dummy half sending Lomax clear and the scrum half converted to fire his side ahead 10-4 after 14 minutes.
Widnes levelled with a magnificent solo try from Rhys Hanbury when the scrum half took Jon Clarke's pass to surge past Lance Hohaia and beat Wellens to touch down under the posts with Ah Van landing the conversion.
Roby was in lively form for Saints who had won three of their last four games under acting coach Mike Rush and Keiron Cunningham.
Saints pressure told after 30 minutes with Lomax sending Chris Flannery through a yawning gap with Lomax's goal putting his side ahead 16-10.
Hohaia stretched over two minutes later for a try awarded by video referee Phil Bentham and Lomax stretched the lead to 22-10.
Owens saved another try by knocking down a Flannery pass but the Widnes relief was short-lived with substitute Louis McCarthy-Scarsbrook bulldozing over from Roby's pass to make it 28-10 at the break.
White gave the Vikings some hope early in the second half by burrowing over from dummy half to cut the deficit to 28-16.
But Jones' second try ended the Widnes dream with Wellens piling on the agony by collecting a Lomax kick to extend the lead to 40-16 before the frantic finish.