The Warriors deservedly led 10-6 after a hard-fought first period and the second-half scoring went entirely in their favour.
The Reds will be particularly disappointed having gone into the quarter-final tie under the weight of expectation following an improvement in form.
Gareth Hock opened the scoring for Wigan just two minutes into this encounter, Richards adding the conversion for his first points of the night and a 6-0 lead.
The Reds responded quickly, a penalty awarded in an advantageous position leading to a touch down from Luke Adamson, John Wilshere adding the extras to draw level.
Richards edged Wigan back into the lead with a try at the corner, and the hosts’ four-point advantage was maintained until the half-time interval.
Salford began the second half in determined fashion but the first points went to Wigan, Richards converting a penalty before grabbing a second try out wide, the score now 16-6.
Richards then completed his hat-trick with ten minutes left on the clock, Hock the provider for the prolific wingman, Richards then adding a touchline conversion to his own touch down.
Hock, who himself had excelled in the Cherry and White, rounded off the game with his second try after good work from Sam Tomkins, Richards converting to complete the scoring.