Jonny Lomax made the difference as Super League leaders St Helens came from behind in the final quarter to again get the better of nearest rivals Warrington Wolves, triumphing 21-10 at the Halliwell Jones Stadium.
A trio of Declan Patton penalties put the Wolves on course to avenge a 38-12 defeat at Saints earlier in the season and set up an end-of-term race for the League Leaders' Shield.
However, Lomax then played a key role in tries for Mark Percival and Luke Thompson, before Alex Walmsley sealed victory - and an eight-point lead over Warrington at the summit - by crossing at the ground where he broke a bone in his neck last March.
Justin Holbrook's side suffered an early blow when Aaron Smith was carried off in a neck brace after sustaining an injury as he tried to tackle Sitaleki Akauola.
Warrington gradually edged clear thereafter through the boot of Patton but the sin-binning of Jack Hughes, who was rightly yellow carded for catching Tommy Makinson in the face with his forearm, proved a turning point.
With the hosts down to 12 men, a dazzling Lomax break laid the platform for Percival to dummy over in the left corner, amid strong suspicions of a forward pass from Theo Fages.
Lomax then chased down his own high kick superbly and forced Jake Mamo to spill the ball, with Thompson on hand to capitalise and give Saints the lead.
Lachlan Coote converted both scores before adding a drop goal in a dramatic finale that saw Mamo respond immediately with a try from a short kick-off and Walmsley crash over at the other end.
Elsewhere on Friday, Wigan Warriors' revival continued with a 28-12 win over Salford Red Devils, which moves the defending champions up to fourth, while Tyler Randell scored a hat-trick as Wakefield Trinity claimed a much-needed win and pulled clear of the bottom four by beating Huddersfield Giants 36-10.