The Scottish Cup winners soon added to that advantage after Stevie May fired them ahead in the tie from the penalty spot.
Wright's men came within the width of the woodwork from snatching victory in the dying stages of extra time, as second-half substitute Liam Caddis struck the post.
Something had to give during penalties, and it did when Mannus saved Luzern's second of the shootout, before Caddis fired the Saints ahead.
The subsequent spot kicks were infallible from both sides, before Tam Scobbie was charged with the responsibility of firing St Johnstone into the next round, and the defender made no mistake as the Scots progress with a 5-4 shootout victory. body check tags ::