Doncaster booked a surprise trip to Blackpool’s Bloomfield Road with a hard-won 21-12 victory over Batley Bulldogs at Mount Pleasant.
The Co-operative National League Two side faced a stern test against opponents from the league above but sealed their win with tough defence.
The Dons will now face either Celtic Crusaders or Salford City Reds; the two National League One sides meet in Bridgend on Saturday evening.
The visitors opened the scoring with a penalty goal from Kyle Briggs, who tagged on a second when Alex Benson took advantage of a gap in the Bulldogs line to touch down.
Batley were the architects of their own downfall for Doncaster’s next try, a wayward pass from Bolu Fagborun allowing Peter Green to touch down beneath the posts, Briggs converting.
A potential third try was disallowed by the video referee and the Bulldogs reduced the deficit with a try from Andy Boothroyd, Francis Maloney converting and adding a penalty.
Trailing 14-8 at the half-time interval the home side were fired up after the restart, but the Dons’ defence held firm and Wayne Reittie touched down Luke Gale’s kick to extend their lead.
Briggs added a penalty to the visitors’ total but Tim Spears crashed over for Batley, a try awarded on the nod of the video referee, to leave the score at 20-12.
But this try failed to spawn a Bulldogs comeback, Doncaster’s defence winning out in a tough battle, and by the time Gale tagged on a drop goal the game was over as a contest.
Batley – 12T: Boothroyd (36) Spears (64)
G: Maloney (37, 40)
Doncaster – 21T: Benson (14) Green (18) Reittie (47)
G: Briggs (5, 15, 19, 58)
Dg: Gale (74)
HT: 8-14
Ref: R Laughton
Att: 1,044