Paul Ward’s side were without the suspended Harry Millard for the visit of seventh-placed Wisbech as they hoped to bounce back from two narrow defeats.
The visitors came into the game on the back of three wins in their last four league outings.
Neither side were able to carve out clear chances in a tight first half, but Town did have the ball in the net in stoppage-time, only for the effort to be ruled out for offside.
Shaw came on for Hollingworth as Town searched for the elusive breakthrough, but it was the Cambridgeshire side who hit the front midway through the half.
A Sleaford free-kick quickly turned into a Wisbech counter-attack which ended with the visitors being awarded a penalty.
And goalkeeper Sam Vince converted the spot kick for his third goal of the season for the Fenmen.
With Town now chasing the game, Michael Frew snatched a second eight minutes later, and Wisbech wrapped up the points with 10 minutes left when Liam Adams finished off another counter-attack for 3-0.
Sleaford remain 17th in the United Counties League Premier after the loss and seven points clear of the bottom three with just five matches of the season remaining.
Saturday brings a trip to Oadby Town who sit just two places and four points beneath Town. Kick-off is 3pm.
The sides have yet to meet this season with Oadby due at Eslaforde Park on the final day of the season.
Town: McGann, Worthington, Andersen, Elliott, Ward, Braithwaite, Siddons, Rushen (Fenton), Hollingworth (Shaw), Smith, Asplin (Machin).
* Town’s scheduled trip to Wisbech on Saturday, April 15 has been brought forward 24 hours.
The Premier Division clash will now take place on Good Friday with a 1.30pm kick-off.