After being held to a draw in Kazakhstan on Saturday, Belgium still had work to do to secure their place at next summer’s showpiece.
However, they were heavily fancied to get the job done against their lowly opponents, and their status as favourites was justified inside just three minutes.
Captain Youri Tielemans’ cross took a nick off a defender and looped in the air for Hans Vanaken to nod home at the back post for the opener.
Rudi Garcia’s men kept the pressure on, with Liechtenstein camped inside their own penalty box for most of the first half.
Tielemans had an effort cleared off the line by Andreas Malin, with Thomas Meunier’s follow-up held by the grateful Benjamin Büchel.
Nevertheless, there was nothing the Blue-Reds keeper could do just after the half-hour mark when Alexis Saelemaekers’ cutback was swept home first time into the bottom corner by Jérémy Doku.
The Manchester City forward wasn’t done there, and he made the visitors pay following a stray clearance.
He still had work to do with the ball at his feet on the edge of the box, but he skillfully jinked past two defenders and hammered a low shot into the net.
The Red Devils were well in control and not even a HT rest could stem the tide.
Seven minutes after the restart, another delicious Tielemans ball bore fruit as Brandon Mechele stabbed home from Charles De Ketelaere’s flick-on for his first international goal.
That laid the foundations for an onslaught, with three more goals coming before the hour mark.
First, Saelemaekers mopped up a rebound after Büchel spilt a shot before a quickfire brace from De Katelaere.
After finishing from a narrow angle, he subsequently flicked home Meunier’s volleyed effort.
This took the hosts past the six goals they scored in Vaduz in September on another sorry night for the side ranked 206th in the world - they ended up conceding 31 goals in total in qualifying without scoring a single one in return.
For Belgium, they will be in North America next summer for their fourth consecutive FWC.
Flashscore Man of the Match: Youri Tielemans (Belgium)
