St Helens have given themselves a great chance of making the top four, triumphing in the derby with an impressive 23-4 victory against Wigan at the DW Stadium.
A great defensive display from the visitors saw them deny Wigan from scoring a single point in the second half.
Then Lewis Tierney grounded the ball in the corner to send Wigan 4-2 in front after a brilliant kick from George Williams.
Percival continued to have a big influence on the game, touching down after taking Lomax’s pass before nailing the following conversion to put Saints 10-4 ahead six minutes before the interval.
Tomkins thought he had crashed over but Joe Greenwood came to the rescue, adjudged to have held the ball up after confirmation from the video referee in a brilliant tackle.
Luke Walsh’s drop goal seven minutes from time put further daylight between the two sides.