Wigan will face Warrington at Old Trafford after seeing off Hull FC 28-18 in a dramatic circumstances at the DW Stadium.
Wigan eliminated the Black and Whites, and secured their place in the grand final for the fourth time in a row, after an epic encounter.
Farrell and Tierney combined once more, before the latter crashed over for his second try in six minutes.
Smith then added the extras to give the Warriors a commanding 14-0 lead at the interval.
A penalty from Smith curbed the pressure from the Black and Whites and re-established the Warriors’ one-score lead.
But then the drama went up several notches. Just as the video referee played a key part in defining last night’s result, Ben Thaler overturned the on-field decision from Robert Hicks to deny Steve Michaels a try.
Oliver Gildart had ran the length-of-the-field and crashed over at the other end but that was ruled out, with Michaesl effort awarded.
That tied the scored up and then Sneyd added the extras to push Hull FC 18-16 in front with 16 minutes left.
But Wigan would have the final say. The game continued to draw to a dramatic conclusion as Sam Powell dived over under the sticks to put the Warriors back in front with nine minutes left.
If there was any doubt then among the Wigan supporters about whether they would be going to the Theatre of Dreams next week, Anthony Gelling made sure of victory by racing over in the corner in the 78th minute.