Germany eventually wore down Liechtenstein resistance as they beat the minnows 2-0 in Hansi Flick's first game in charge.
Chelsea's Timo Werner slotted the ball between Benji Buchel's legs from Jamal Musiala's pass to give the Germans a 41st-minute lead.
Leroy Sane sealed the win with a fine solo goal in the second half.
Germany had a total of 29 shots in St Gallen, Switzerland, including Robin Gosens heading off the crossbar.
Former Bayern Munich manager Flick replaced long-serving Germany boss Joachim Low after Euro 2020.
They still sit one point behind Group J leaders Armenia, who drew 0-0 with North Macedonia.