The Challenge Cup kings are at it again. For the first time in a good while, Wigan were arguably underdogs going into this semi-final against their fiercest rivals, St Helens, with a run of form that included four successive Super League defeats before stopping the rot last week against promoted Bradford. In contrast, St Helens are joint-top of Super League and have won their past five, but when it comes to Wigan and the Challenge Cup, this relationship is anything but ordinary. For the 34th timethe Warriors have reached the final. Wigan were sensational at both ends of the pitch, proving far too strong for Saints. Paul Rowley may point to the loss of his captain and influential forward, Matty Lees, after the opening tackle of the game as a major factor for their limited display. But he, and any St Helens supporter, could have no complaints after being comprehensively outplayed.…