Ali netted late on in Qatar's victory over Lebanon in their opening fixture and the 22-year-old was on top form as the World Cup 2022 hosts stormed into the last 16.
After expertly turning home Akram Hassan Afif's cross, Ali doubled his tally two minutes later, having latched onto a superb delivery from Hasan Al Haydos.
Ri Un-chol went close to pulling one back for North Korea, who were reduced to 10 men late on, but the result was put beyond all doubt when Boualem Khoukhi headed in on the stroke of half-time.
Ali had his third – and the tournament's first hat-trick – 10 minutes after the interval, subtly nudging Afif's weighted throughball past the onrushing Ri Myong-guk to overtake Iran's Sardar Azmoun as the 2019 Asian Cup's leading scorer.
Qatar did not let up though, piling further humiliation on North Korea as Afif and Ali again combined for the latter to drill in his fourth on the hour, with the woodwork denying the striker another goal moments later before left-back Abdelkarim Hassan made it six at the culmination of a surging run.
GOAL ! 60' Al Moez Ali registers his fourth of the game! What a performance from the Qatari star!— #AsianCup2019 (@afcasiancup) January 13, 2019
DPR Korea 0-5 Qatar pic.twitter.com/qxeMFTRA0w
Matters were made worse for North Korea in the 90th minute, Jong Il-gwan receiving his second yellow card for a reckless lunge on Khoukhi.
Felix Sanchez's side now top Group E and a point against already qualified Saudi Arabia on Thursday will see them secure pole position.