Andreas Skov Olsen, Simon Kjær, Christian Nørgaard and Joakim Mæhle scored for the Danes in a solid first half, and Moldova were never close to threatening the guests.
Denmark also completely dominates in qualifying group F and is seven points ahead of second Scotland with three games left. This means that one win in three attempts will be enough to secure a place in the Qatar World Cup next year.
Saturday’s match was a one-way affair in Chisinau. Moldova did not score a single goal, and the match was prepared within 20 effective Denmark minutes before the break.
Earlier on Saturday, Scotland tightened their grip on second place in the group by beating Israel 3-2. Israel and Austria are four points behind the Scots.
European World Cup qualifiers for footballers Saturday, 7th match day:
Azerbaijan-Ireland 0-3 (in Baku), Luxembourg-Serbia 0-1 (in Luxembourg by).
Georgia-Greece 0-2 (in Batumi), Sweden-Kosovo 3-0 (in Solna).
Lithuania-Bulgaria 3-1 (in Vilnius), Switzerland-Northern Ireland 2-0 (in Geneva).
Kazakhstan-Bosnia-Herzegovina 0-2 (in Nur-Sultan), Finland-Ukraine 1-2 (in Helsinki).
Scotland-Israel 3-2 (in Glasgow), Faroe Islands-Austria 0-2 (in Torshavn), Moldova-Denmark 0-4 (in Chisinau).
Andorra-England (in Andorra la Vella) 0-5, Poland-San Marino (in Warsaw) 5-0, Hungary-Albania (in Budapest) 0-1.