Jozef Piaček headed in the only goal as MŠK Žilina, group stage participants two seasons ago, condemned Hapoel Kiryat Shmona FC to defeat in their first UEFA Champions League match.
It seemed the hosts' chance of establishing a lead to carry into next Tuesday's second qualifying round second leg had lapsed when impressive Kiryat Shmona goalkeeper Daniel Amos saved Ricardo Nunes' 81st-minute penalty. Piaček, however, redeemed his team-mate by directing in captain Miroslav Barčík's corner 60 seconds later.
Amos frustrated the Slovakian side on more than one occasion before he was eventually beaten, denying Momodou Ceesay early on from a tight angle and then Piaček from Nunes' centre. The same players combined again a minute later, Piaček getting the slightest of touches to a cross only for the ball to strike the crossbar.
The visitors responded with Shimon Abhazira shooting wide in their first incursion into the Žilina penalty area, while after the break Sali Hassarmi struck the bar when it appeared easier to score following David Solari's corner.
The grounded Amos then somehow thwarted Ceesay and, a quarter of an hour later from the penalty spot, Nunes, but Piaček made sure Frans Adelaar's men had something to work with going into the return leg next Tuesday.