impressive 58-14 victory over Normanton Knights with a home tie against Betfred League One side Doncaster in the third round of the Coral Challenge Cup.
It will be the first time since 2007 that Thornhill have played in this stage of the competition when they faced Keighley Cougars.
The ties are scheduled for next weekend (February 8 and 9) with Thornhill to announce a venue for the clash in due course.
The community clubs left in the competition will be aiming to reach the fourth round when Championship clubs enter.
The British Army, who beat the Hull amateurs Skirlaugh at their Aldershot base in golden point extra time last Saturday, will now host Ince Rose Bridge of Wigan .
Of the 11 League 1 teams who enter the competition at the third round stage, Keighley Cougars will face Newcastle Thunder in a meeting of two of the pre-season promotion favourites.
Bentley, the Yorkshire Men’s League champions and lowest ranked team left in the cup, have a tough trip to Leigh Miners Rangers.
Rochdale Hornets will host York Acorn of the National Conference League, while Rochdale Mayfield face semi professional opposition in North Wales Crusaders.
Underbank Rangers face a long trip to West Wales Raiders with London Skolars paired away to Barrow.
Hunslet host their League 1 rivals Coventry Bears, and there will be an all-National Conference League showdown between Siddal and West Hull and West Bowling face a long haul to face Workington Town.
One Third Round tie will be selected for live streaming by BBC Sport, and another by the RFL’s Our League app.
Challenge Cup Third Round: Workington Town v West Bowling, British Army v Ince Rose Bridge, Leigh Miners Rangers v Bentley, Rochdale Mayfield v North Wales Crusaders, Thornhill Trojans v Doncaster, Siddal v West Hull, Barrow v London Skolars, Hunslet v Coventry Bears, Keighley Cougars v Newcastle Thunder, Rochdale Hornets v York Acorn, West Wales Raiders v Underbank Rangers.