KNIGHTS returned to winning ways in wet and windy Wales.
Lynn Howells, furious at his side's defeat to struggling Birmingham & Solihull in last week's league and cup double-header, made six changes to his starting XV.
And they responded with a spirited performance against the Welsh Premiership side to get off the mark in this season's British & Irish Cup.
First half tries from PJ Gidlow and Zack Farivarz, both converted by Tristan Roberts, gave Doncaster a foothold in the game.
Roberts kicked two penalties to increase the deficit and, although the Doncaster pack dominated in the atrocious weather conditions, it was not until stoppage time that Gidlow added try number three from close range.
Knights face Welsh Premiership leaders Pontypridd at Castle Park on Saturday in the same competition (2.30pm).
* For the latest Knights news see this week's Free Press.