Colts lifted the Doncaster & District Challenge Cup earlier this month by beating Blake Cairns Foundation 4-3 at the Eco-Power Stadium.
But their hopes of a cup double were ended by the Edlington side for whom Ryan Ambler scored twice and Ben Clark and Toby Humphries also found the net.
Another cup winning team, Bentley Village, lost out in the other semi-final which was a much closer affair.
Bentley won the Division One KO Cup thanks to a 2-1 victory over Adwick Park Foresters.
But they were beaten 4-2 in a penalty shootout by Airmyn FC after a 1-1 draw in regulation time.
Josh Lamming scored for Airmyn, while Aiden Davies replied for Bentley.
There were no Premier Division games in the latest round of fixtures so all eyes were on Division One and particularly the battle for the title.
Leaders Adwick Park Foresters moved five points clear of second-placed Bentley Village, who were in cup action, with a 6-1 demolition of AFC Bentley Development, although Village do have two games in hand.
A hat trick by Jack Roberts, brace for Connor Moor and a John Gaskin goal did the damage for the Foresters, while Callum Agar netted for Bentley.
Old Club FC enjoyed a 5-0 success over Hemsworth Town with goals from Clayton Cherowbrier (2), Bradley Sparrow (2) and Callum Hutchinson.
FC Doncaster A drew 1-1 with FC Bessacarr Development.