Salisbury came away from Dorchester empty-handed after a goal that looked to be offside gave the home side a 1-0 victory.
Brian Dutton rang the changes ahead of the game with Aaron McCreadie returning from injury and Alex Rutter starting after the end of Harry Lee's loan spell.
Salisbury were dealt an injury blow early on when Levi Irving, who was starting a match for the first time, was forced off after picking up a knock. He was replaced by Tom Leggett, which meant a change in formation for the Whites.
Salisbury were undone on the break after 25 minutes. A Charlie Gunson freekick was saved by Jameson Horlick before Dorchester broke down the other end of the pitch and scored controversially.
Olaf Koszela's effort seemed to hit the inside of the post before Shaquille Gwengwe, who was in an offside position, appeared to apply the finishing touch to put it across the line.
Salisbury's keeper Alex Rutter led the appeals as he raced towards the assistant referee, but his and others' calls for offside were waved away.
The Whites, in blue, responded well at the start of the second half. Sido Jombatti rattled the crossbar from a short corner routine after 69 minutes.
While Salisbury had most of the play in the second period, Dorchester were dangerous on the break, and Alex Rutter helped keep the deficit to just one goal.
Salisbury huffed and puffed but could not level the game and slipped to third in the league following the defeat.
Up next for Salisbury is a trip to Swindon Supermarine on Saturday. Kick-off is at 3pm.
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