Dominic Calvert-Lewin stepped off the bench to score the only goal of another tedious contest as Everton booked their expected place in the Europa League playoff round.
The 20-year-old striker came on for full debutant Sandro with 20 minutes to go and when he was set away into space behind the Ružomberok defence, he made no mistake with an accomplished finish past the stranded goalkeeper.
It was a moment of rare incisiveness from the Toffees who again toiled against the well-drilled Slovakian side despite having a further week of pre-season under their belts.
Ronald Koeman started Sandro for the first time in a forward role alongside Wayne Rooney and deployed Tom Davies in a wing-back role to the right of a three-man central defence but the team was generally devoid of pace, urgency and imagination.
As was the case in the first leg, the Blues had the bulk of the possession in the early going but struggled to make inroads into Ružomberok's defence despite Sandro's willing running.
It was the home side who had the first half chance when Kruzliak popped up with a free header after five minutes but could only plant a header well over the bar.
Five minutes later, Eric Daniel crossed low with Hazkic lurking but Pickford was on hand to block the ball before it could reach him.
For Everton, Rooney tried an ambitious chip that cleared the crossbar and Michael Keane drove an attempted shot following a corner well wide after Sandro had delayed his shot and seen an effort deflected behind.
The Spaniard then had a chance from a similar position but fired over from a tight angle before half time.
The Slovakians began the second period briefly on the front foot and Daniel drifted a speculative effort over the bar while at the other end, Sandro sliced wide after space momentarily opened up in front of him.
It was Daniel who went the closest so far of either team when he curled a deep cross towards the back post that may have grazed the woodwork on its way tio the far side.
Sandro was the one sacrificed when Koeman decided to make a change with a little over 20 minutes left, making way for Calvert-Lewin as Everton continued to toil against Ružomberok's disciplined rearguard.
And it was the youngster who made the difference to a dreadful game, latching onto Klaassen's first-time pass to slow coolly past the goalkeeper and potentially seal the tie 10 minutes from time.
Kick-off: 7:45pm BST, Thursday 3rd August, 2017
Everton: Pickford, A. Williams, Keane, Jagielka, Baines, Schneiderlin, Gueye, Klaassen, Davies, Rooney, Sandro
Subs: Stekelenburg, Martina, Barry, Holgate, Lookman, Mirallas, Calvert-Lewin
Everton take their narrow 1-0 lead into the second leg of the Europa League Third Qualifying Round, second leg, hoping to finish the job in Ružomberok this evening.
Leighton Baines's deflected strike meant that the Blues edged their unfancied Slovakian opponents at Goodison Park a week ago but Ronald Koeman is confident that with another week of training under their belts, his charges will be more convincing than they were in the first game.
The Blues were somewhat lethargic in that first leg and struggled to impose themselves in a system that had Wayne Rooney as the focal point up front and newcomer Davy Klaassen driving from midfield alongside Idrissa Gueye.
All three are likely to start again in the second leg after Rooney was passed fit despite a minor groin problem but Sandro Ramirez, another debutant last Thursday, is set to make his first start in an Everton jersey after coming on to spark the Toffees into life midway through the second half.
Jordan Pickford, another of Koeman's summer signings, will make his debut appearance now that he has had the benefit of a further week of pre-season work, replacing Maarten Stekelenburg in goal.
Further changes beyond those could be dictated by the manager's chosen formation for the second leg, with some suggestions having been made in the media that the Dutchman has been mulling a five-man back line with three centre halves and two advanced fullbacks.
Baines would be the obvious candidate for the left-sided role and with James McCarthy seemingly out of favour based on last week's squad selection, Tom Davies could be tasked with playing on the right flank. Jonjoe Kenny, an obvious choice for many supporters, has not travelled with the squad as Koeman weighs up whether or not to send the youngster out on loan.
Ružomberok showed at times in the Goodison leg that they weren't overawed by their hosts and, bolstered by their second-leg success in the two previous rounds and spurred on by the obvious need to score, they are sure to be more adventurous this time around.
For Everton, having kept a clean sheet last Thursday, they will know that they could hand themselves a significant advantage with an away goal, particularly an early one that would draw the Slovakians out and create space in their half as they are forced to come forward in search of goals of their own.
As the superior side, the Blues remain the favourites to progress to the playoff round later this month but they can't rest on their laurels and expect to coast through. As Koeman has found out to his cost in this competition before, the job is there to be completed and that underdogs can bite.
Kick-off: 7.45pm BST, Thursday 3rd August, 2017
Predicted Line-up: Pickford, Martina, Keane, Jagielka, Baines, Schneiderlin, Gueye, Klaassen, Mirallas, Rooney, Sandro