The Daniels went down 2-1 to Belper Town in front of an excellent crowd of 984 at the Zeeco Stadium.
Stamford went into the tie as the division’s form team with nine successive wins, and they’d beaten these opponents Belper twice in the league already this season.
They almost took the lead inside 30 seconds when Jonathan Margetts drilled a shot against the inside of a post, but they then found a stubborn visiting defence tough to breach.
Stamford were still the better team, but the game drifted away from them in a couple of minutes just before the break.
First Brodie Litchfield open the scoring skilfully on 40 minutes and then powerful Stamford centre-back Marshall Willock was sent off after picking up his second caution of the night. The second yellow looked extremely harsh.
Stamford missed a glorious chance to equalise early in the second-half when they were awarded a penalty for a foul on Margetts, but Harry Vince saw his spotkick saved by Lewis Gwilliams who was up smartly to block Margetts’ follow-up shot.
The hosts lost their way in the final quarter and Belper claimed their second goal through Kyle Dixon in added time just before Cosmos Matwasa claimed a consolation strike.