Chris Sang’s goal ensured Guiseley did the double over their Yorkshire rival in the space of a week.
Guiseley joint-manager Marcus Bignot was delighted with how his side performed.
“It was always going to be a tough game for us, the application and attitude of the team got us through this challenge.”
Farsley Celtic boss Adam Lakeland knows his team must aim to bounce back.
“We’ve had a good run and want to start another one soon, we’re still in a great position, it was a game of fine margins and they got the goal.”
The hosts nearly took the lead with just five minutes gone, as a cross found Akeel Francis who just could not sort his feet out and he missed the chance to score against his old club.
Guiseley’s Chris Sang scored a wonder-goal against Farsley the week before and he nearly got another, when he saw a shot on the edge of the area go just over the crossbar.
There was little to separate the sides in terms of possesion and chances, as they both battled in midfield to try and get a real foothold in the match.
The hosts so nearly took the lead with just over an hour gone. When Jordan Richards fired a free-kick on the edge of the area towards goal, it looked to be curling in but just went wide.
The deadlock was broken with Sang being in the right place to score a tap-in.
A Brad Nicholson throw was flicked on at the near post and the striker was at the far post and simply couldn’t miss to give the visitors the lead.
Guiseley held on to secure the win and move just outside the play-off places with Farsley still in the top seven.
Farsley Celtic: Trenerry, Richards, Allen, Higgins, Ellis, B Atkinson (Walton 76), C Atkinson, Syers, Francis (Spencer 72), Cartman (Parkin 76), Hayhurst. Unused subs: Wynne, Clayton.
Guiseley: Dewhurst, McNally, Nicholson, Jones, Bencherif, Digie, Felix (Shaw 83), Cantrill, Sang, Soleman, Johnson. Unused subs: Smith, Barkers, Clayton, Newall.
Referee: Mike Barlow.
Bradford Park Avenue, meanwhile, went down 2-1 at York City.
Avenue, propping up the National North table, gave a valiant account of themselves against the side second on the ladder, four off Kings Lynn Town and six ahead of third-placed Chester.
Bradford Park Avenue are now 10 points from the safety of third-bottom, the position currently occupied by Kettering Town.
Blyth Spartans are second-bottom, on on 17 points, five ahead of Park Avenue.