The 22-year-old, looking increasingly assured at full-back, claimed a hat-trick of tries and kicked a near-perfect eight goals as Saints broke the Wildcats' resistance at Langtree Park.
The hosts ran in nine tries in total in what ultimately proved a dominant display with Jordan Turner crossing twice and Alex Walmsley, Louis McCarthy-Scarsbrook, Tommy Makinson and Lance Hohaia also getting over.
Despite trailing, Wakefield had been competitive at 28-18 midway through the second half but Lomax changed the course of the game with two tries in quick succession.
Wakefield, despite another try-scoring display from in-form winger Ben Cockayne and showing plenty of spirit, left the field dejected after a tough closing period.
Richie Mathers and Dean Collis also crossed for the Wildcats.