John Parkin rescued a draw for York at fellow strugglers Woking after they fell behind in the second half.
However, Torquay's win over play-off chasing Dover Athletic dropped Gary Mills' men into the relegation zone.
Torquay also climbed above Gusieley who remain one place and one point above the Minstermen after hitting back to earn a point against Bromley.
Bromley took the lead early on as Bradley Goldberg's right-footed effort flew past Jonny Maxted in goal.
Guiseley were given a glimmer of hope when Jordan Preston cut in from the left and fired into the bottom right corner to draw level.
Bromley pushed for a winner and Toby Sho-Silva saw his chip agonisingly come back off the post. Guiseley now go into the last game of the season just one point above the relegation zone.
Already relegated North Ferriby crashed to a 3-0 defeat against Aldershot Town.