It was Guiseley's first league victory since 30 April - and the manner of it was enough to see the club trending on Twitter.
The game featured seven goals, a 37-minute delay when the lights went out and an angry fan marching on to the pitch to confront York City boss Jackie McNamara.
York, relegated from League Two last season and backed by more than 700 fans for the away trip, dropped to 20th with a fourth straight defeat.
Guiseley remain bottom with six points from 14 games.
The visitors led through Matt Fry's header, only for Guiseley to scores twice in three minutes through debutant Jake Cassidy and Alex Purver.
Purver added a third, Jordan Preston made it 4-1 and, after the floodlight failure plunged the ground into darkness, Jermaine Hylton, another debutant, and Rob Atkinson completed the rout.
The game, which started at 19:45 BST, finished at 22:35.
Match ends, Guiseley 6, York City 1.
Second Half ends, Guiseley 6, York City 1.
Goal!  Guiseley 6, York City 1. Robert Atkinson (Guiseley).
Substitution, Guiseley. Adam Boyes replaces Jermaine Hylton.
Substitution, Guiseley. Michael Rankine replaces Jake Cassidy.
Substitution, Guiseley. Nicky Clee replaces Connor Brown.
Substitution, York City. Kaine Felix replaces Justin Johnson.
Goal!  Guiseley 5, York City 1. Jermaine Hylton (Guiseley).
Substitution, York City. Fraser Murdoch replaces Scott Fenwick.
Substitution, York City. Yan Klukowski replaces Ben Clappison.
Second Half begins Guiseley 4, York City 1.
First Half ends, Guiseley 4, York City 1.
Goal!  Guiseley 4, York City 1. Jordan Preston (Guiseley).
Jordan Preston (Guiseley) is shown the yellow card.
Goal!  Guiseley 3, York City 1. Alex Purver (Guiseley).
Goal!  Guiseley 2, York City 1. Alex Purver (Guiseley).
Goal!  Guiseley 1, York City 1. Jake Cassidy (Guiseley).
Goal!  Guiseley 0, York City 1. Matt Fry (York City).
First Half begins.
Lineups are announced and players are warming up.
National League bottom club Guiseley came from behind - and overcame a floodlight failure - to thrash Yorkshire neighbours York City at Nethermoor.