A pair of penalties from the lively Terry Hawkridge in the first half was more than enough for the Blues, who were rarely troubled by their lower league opponents.
For Steve Housham’s Trinity Hawkridge and fellow midfield men Shane Clarke and Jonathan D’Laryea impressed, while Paul Connor worked hard for nearly 80 minutes up front on his own.
Early pressure from the visitors saw former Gainsborough man Owain Warlow burst into the box and win a corner, but Lee Beeson’s delivery was collected easily by Jan Budtz.
At the other end the Blues were given a free-kick level with the box on the left and the delivery caused problems for Worksop, who had to block two shots in quick succession.
Hawkridge sent a low drive wide of the Worksop goal after a scrappy opening 12 minutes.
Jamie Yates then stung the hands of former Boston United keeper Paul Bastock with a free-kick that fizzed towards the left corner of the net.
The stopper was back in action seconds later to deny Connor’s free header from six yards.
With 19 minutes gone an offside trap failed the visitors and Connor ran through alone on Bastock, the striker going down over his challenge to win a penalty.
Hawkridge took it and blasted home for the opening goal.
Beeson sent a dangerous ball into the Gainsborough box from a left sided free-kick but no one got a touch at the far post as they looked to level.
A change in formation for Worksop brought a better spell, but a lack of a killer ball meant Budtz was relatively untroubled.
But it was 2-0 to the home side on 33 minutes, and again it was a Hawkridge spot-kick.
The ball dropped to Ryan Clarke, he controlled in his own box and didn’t spot Hawkridge behind him, tripping the Trinity youngster with his second touch.
Former Carlton man Hawkridge picked himself up to stroke home his and Gainsborough’s second.
Beeson curled in a 25 yard effort as Worksop looked to hit back straight away but Budtz was equal to it.
Michael Leary blasted just over as Trinity went seeking a third in the final minute of the half, the 20 yard half volley not missing by much.
Just 20 seconds of play had elapsed after the break when Tigers gifted possession to the Blues and Hawkridge appeared to be felled again in the box, but the referee turned the appeals down.
Clarke fired a right-footed shot off target for Gainsborough as he got forward in support of Connor.
Hawkridge played a lovely ball through for lone striker Connor and although he got wide of Bastock, there was no one to get on the end of his cross.
Neither side created much for a prolonged period, but it was the men in yellow who played the better football.
A number of substitutions interupted what flow there was, although Worksop finally put together a cohesive attack as Steve Towers almost found Beeson in the box before Budtz cleared.
The final stages took on a familiar pattern, Trinity playing slightly better stuff but with no end product and Worksop toiling to put forward passes together.
Housham’s men host Grantham Town in the semi-final of the Lincs Cup on Saturday (3pm).
Gainsborough: Budtz, Roma, Ridley (Wilde 64), Waterfall (Hone 75), Young, Leary, D’Laryea (J. Williams 75), Hawkridge, S. Clarke (Williams 69), Connor (Mulready 78), Yates (Banks 69). Subs: Stamp, White.
Worksop: Bastock, R. Clarke (Ludlam 71), Craven, Young, Shiels, Hawes, Beeson, Towers, Holden (Menga 84), McDonald (Melton 76), Warlow. Subs: Wood, Davies, King, Ziccardi.
Referee: Colin Unwin. Assistants: David Heap, Wayne Escreet.