Doncaster completed a Championship double after putting North Wales Crusaders to the sword at The Rock.
But they were made to battle all the way by a lowly Crusaders side in a game which went down to the wire.
The Dons were well below their best on the day, but once again their never-say-die spirit saw them claim the spoils.
The Dons broke the deadlock after an even opening when centre Liam Welham crossed from close range on 13 minutes following some neat handling along the line.
The visitors increased their lead four minutes later, scrum-half Richard Wilkinson latching on to a dropped ball 25 metres out and sent the supporting Richard Whiting over. Dave Scott added the extras to give his side a flattering 10-0 lead.
The Welsh side hit back on 22 minutes with a converted try in the corner by winger Greg Wilde after his opposite number Stu Sanderson had fumbled a kick through close to the line.
The Dons came more into the game after an indifferent spell when mistakes started to creep into their game, player-coach Paul Cooke being forced into touch just short of the line.
Crusaders winger Dan Birkett suffered the same fate five minutes later.
Crusaders weren’t to be denied, however, and took the lead just before the break with a converted try by Rearden.
The Dons kept the ball alive after the hooter had sounded only to have a touchdown by Sanderson disallowed for a forward pass.
Crusaders went close to a third try just after the break, before Mike Kelly dropped Cooke’s try-scoring pass close to the line.
The home side rode their luck and Birkett touched down in the corner for a 50th minute converted try after the ball had been shipped from right to left.
At 18-10 down the Dons had it all to do. Scott Spaven threw his side a lifeline at the end of the third quarter when darting over from acting half-back, near enough for Scott to convert.
Craig Robinson produced a try-saving tackle on full-back Tommy Johnson on 65 minutes, only for Seb Martins to go over seconds later.
Johnson’s conversion restored Crusaders’ eight point lead.
But Cooke put Emmett over from close range for a converted try three minutes later and a converted 72nd minute try by Steve Snitch edged the visitors into a 28-24 lead.
*Dons: Scott, Sanderson, Welham, Waterman, Hodson, Cooke, Wilkinson, Carbutt, Kesik, Snitch, Whiting, Kelly, Emmett. Subs: Spiers, Robinson, Spaven, Colbon.
Referee: Dave Merrick.