The Polish side secured the goalless draw in the remote Arctic Circle town of Bodø, in Norway's far north, after an uninspiring performance on Thursday, Polish state news agency PAP reported.
Lech play Bodø/Glimt in the second leg next Thursday, February 23, in Poznań, with kickoff at 9 p.m.
The winners of the play-offs will progress to the last 16 of the competition.
The Polish team reached the knockout stages of the Europa Conference League after finishing runner-up in its Europa Conference League group in November.
Lech in May won the Polish premier league championship for the eighth time.
(gs)
Source: PAP