This was Stamford’s fourth straight home defeat in all competitions and the result leaves them perilously close to the drop zone.
Stamford paid the price for another poor first half display and, as they against Whitby on Saturday, found themselves 2-0 down at the interval.
The Daniels were without skipper Richard Jones and Jon Challinor, both missing through suspension.
Anthony Griffin Junior put Barwell ahead after just ten minutes when he was allowed too much space to cut in from the left and deflect a shot past Alex Lynch at his near post. Lynch had saved well with his feet minutes before this as Barwell started at a high tempo.
Stamford very nearly levelled soon after when a through ball from Andy Burgess saw the visiting goalkeeper James Hogarth-Wren sprint out of his area. Ryan Robbins beat him to the ball but his poked at effort trickled wide of an empty net.
Stamford continued to be wasteful in possession and, in turn, allowed Barwell too much space on the ball.
This was typified with their second goal on 37 minutes. Luke Barlone, having picked up the ball on the edge of the Stamford box, was allowed to turn and pick his spot as the ball struck the underside of the bar and flew in.
At half time manager David Staff introduced Richard Wesley in place of David Moyo and played Robbins more central alongside Jordan Smith up front.
Stamford had their chances in the second half. Robbins was denied by Hogarth-Wren with a low save when one on one and Ryan Walker then saw a powerful long range effort brilliantly saved.
Robbins struck a volley over when unmarked at the edge of the six yard box and also drove an effort wide from a tight angle late on.
Barwell had their chances too. Lynch did well to save two one ones at close range with his body and, when he was beaten, the inside of the post came to his rescue.
The final whistle went on a frustrating evening at the Vic Couzens Stadium and Stamford now face a tough trip to Worksop who have scored 24 goals in their last six matches.
One positive from the night was that Walker made it through 90 minutes after returning from injury and looked assured on the ball.
STAMFORD: Alex Lynch, Ashley Robinson, Nathan Haines, Alvin Jarvis, Ryan Walker, Jack Ashton, Shawn Richards, Andrew Burgess (Liam Richardson), Jordan Smith, David Moyo (Richard Wesley), Ryan Robbins. SUBS Not used: Dan Lawlor, David Staff and John Feetham
BARWELL: James Hogarth-Wren, Scott Lower, Daniel Spencer, Declan Towers, Jamie Hood, Jack Edwards, Daniel Quinn, Scott Hadland, Luke Barlone, Anthony Griffith Jnr, Connor Gudger. SUBS: Kieron Brehon, Thomas Weale, Luke Richards and Nigel Julien.