Blues boss Chris Hardy was true to his word making only modest changes for this return to his former club and Whitby's to the North Riding Senior Cup on Tuesday night.
Matty Tymon was unavailable up front as newcomer Kyle Fryatt, signed from Whitley Bay earlier in the day, debuted and assistant boss Lee Bullock again enjoyed 90 minutes in the centre of defence as Luke Bythway stepped aside.
Mikey Roberts, one of five ex-Guisborough players in the Whitby starting line up, tested the hosts' dual registered on-loan Blues gloveman James Dawson before Fryatt showed the way to go on seven minutes.
The diminutive former Shildon wide man controlled well on the edge of the box before slotting into the bottom-left corner, giving Dawson no chance.
Another player with joint loyalties then came close for Guisborough as Jamie Poole glanced a close range header wide. But Whitby effectively won it with two goals in five minutes late in the first half.
First, the outstanding Dale Hopson scored an outstanding goal, blocked by three home defenders he impudently chipped the lot of them and keeper Dawson for Town's second before exchanging passes with Connor Smith who crossed from the right for Fratt to turn in point-blank at the back post.
Three minutes into the second half and it was four. Hopson was up to his old tricks again, taking on two players and lobbing from the right edge of the box into the top-left corner.
At the other end, the lively Tom Bligh saw a 25-yard drive deflected narrowly over the top and Sam Orritt's free-kick from similar range was touched over by Shane Bland. Hopson completed his hat-trick on the hour when Mikey Roberts was dragged down, off the ball, at the back post, as a left-wing corner was taken short.
The ex-Darlington midfielder tucked into the bottom-right corner from the resulting penalty, making way for Anthony Hume, five minutes later.
Whitby Town: Bland, Smith, McWilliams, May, Bullock, Robinson (c), Gell, Hopson (Hume 65), Roberts, Fryatt, McTiernan. Subs not used: Dixon (GK), Anderson, Martin, Weledji.