Saints snatched a last-gasp victory for the second time in a week to go top of the First Utility Super League, at least for 48 hours.
The reigning champions needed a last-minute drop goal to beat Huddersfield 35-34 last Friday and on Thursday night scored a dramatic try two minutes from the end to secure a 20-14 derby win over Warrington.
Centre Jordan Turner’s touchdown completed a hat-trick of wins for Saints over their arch rivals, who are now unlikely to finish in the top four.
The Wolves enjoyed the better of the opening moments with Stefan Ratchford a constant danger in his latest position of centre and hooker Daryl Clark producing some lively runs from dummy half.
St Helens lost skipper Jon Wilkin with a thumb injury after only seven minutes but they made the most of back-to-back penalties to mount a sustained spell of pressure on the Wolves line.
Forward Louie McCarthy-Scarsbrook was twice held agonising short after strong bursts but there was no stopping hooker James Roby when he burrowed his way over from dummy half on 14 minutes.
Luke Walsh added the conversion and extended his side’s lead to 8-6 on 18 minutes with one of 16 penalties awarded in the first half alone by referee James Child.
Despite the stop-start nature of the game it was still fast and furious, and the intensity of both teams’ defence left no-one in any doubt of their desire to claim the two points.
At one stage the game was stopped for St Helens second rower Joe Greenwood to have treatment after taking an accidental blow from his own team-mate Mose Masoe in a tackle that went wrong.
The Wolves enjoyed the better of the second quarter and would have scored had centre Ryan Atkins’ pass found his winger rather than the touch judge after neat passing pulled the visitors defence out of position.
Substitute prop Anthony England was denied a try by a forward pass, to furious protests from the home side, but they finally gained some joy three minutes before the break when second rower Ben Currie took Ratchford’s pass to slip through a gap in the Saints defence for a try.
Gareth O’Brien converted to cut the gap to two points and Warrington hit the front nine minutes into the second half.
Aggressive defence kept St Helens pinned inside their own 20-metre area and, when Walsh tried to run the ball out of danger, his pass was picked off by winger Kevin Penny for an opportunist try, which O’Brien converted to make it 12-8.
The lead lasted just five minutes, however, as the 19-stone Masoe began to make his considerable presence felt.
Clark did terrifically well to bring him down on his own following one charge but the Samoan heavyweight swatted off five defenders on his next run which took him all the way to the line.
Walsh’s third goal made it 14-12 to the visitors but the game continued to ebb and flow, especially with less involvement by the referee.
Warrington fans thought their side had scored again when substitute forward Joe Philbin took Matty Russell’s pass to go through a gap but he had the ball knocked from his grasp in the act of scoring by Saints centre Jordan Turner.
Atkins was then thwarted by a ball steal as he attempted to touch down but O’Brien levelled the scores with the subsequent penalty.
Before either side could line up a drop-goal attempt, St Helens full-back Adam Quinlan, hat-trick hero on his debut a week earlier, broke out of his own half and the champions kept the ball alive superbly to work Turner over at the corner with just two minutes left and Walsh kicked his fourth goal.