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