And they managed to squeeze into the Second Round after a winner in stoppage time of extra-time!
It had been agreed by both clubs that the tie would be played to a finish, with extra-time and penalties if required.
After coming close to opening the scoring in the 13th minute when Danny Johnson couldn't quite turn in a Jordan Preston cross, the home side did take the lead on 29 minutes when Richard Peniket jinked between two defenders before stroking the ball into the bottom corner.
The visitors were level though just before the hour-mark when Alex Purver’s shot was deflected into the path of Rowan Liburd who slammed the ball home from six yards.
Guiseley came close to taking the lead just 2 minutes later another as Mike Fondop-Talom intercepted Fraser Kerr's header back to keeper James Montgomery and hooks the ball over the Heed `keeper, but Kerr was back to head the ball away just in time.
Both sides had chances to win it in what remained in normal time and extra-time, but it was heartbreak at the death for the visiting Lions as sub Theo Vassell poked home Scott Barrow’s cross at the far post in the last seconds olf overtime.
Gateshead will host Boreham Wood on January 13th in the Second Round.