Incredibly, the visitors went into the game having failed to score in an away friendly since a 2-1 defeat to Montenegro in August 2009, including last week’s 0-0 stalemate.
There were few signs of that run ending in the early exchanges as both teams struggled with their final ball, although Francesco Calzona’s side - in the absence of VAR - did have a Dávid Hancko header ruled out for offside as he nodded home from a well worked corner routine.
Róbert Boženík then wasted a glorious chance as he failed to hit the target when meeting a cross from near the six-yard line, while at the other end Kieffer Moore forced a terrific stop out of Martin Dúbravka, who flew high to his right to tip a headed effort around the post.
That save proved crucial, as the hosts took the lead on the stroke of HT when Juraj Kucka wrong-footed Danny Ward with a 25-yard drive that pierced a gap between two defenders on its way into the back of the net.
That paved the way for a dominant second period for Slovakia, who doubled their lead in the 56th minute when Boženík perfectly timed his near post run to get in front of Ethan Ampadu and convert Hancko’s cross from close range.
It was 3-0 shortly afterwards, with Ampadu again involved as he inadvertently chested Lukáš Haraslín’s acrobatic strike past his own goalkeeper.
The Wales response saw substitute Wes Burns have a shot pushed around the post, but the damage had well and truly been done, with László Bénes even adding a fourth with the final kick of the contest.
The Dragons have now won just one of their last 10 away fixtures and have serious questions to answer after an awful international break, whereas Slovakia received the perfect boost ahead of their third successive European Championships by making it back-to-back friendly victories before heading to Germany.
Flashscore Man of the Match: Dávid Hancko (Slovakia)
