The Koreans, in their first Asian Cup match since 2010, dominated the Uzbeks in the Group B opener in Parramatta in western Sydney on Tuesday.
Myong netted her hat-trick in the initial 41 minutes - she was then benched just before halftime - in an ominous display from the three-time champions.
North Korea, who won titles in 2001, 2003 and 2008, haven't featured in the cup since losing the final to Australia in 2010.
The absence came amid a period including doping bans - five players tested positive to prohibited substances at the 2011 Women's World Cup and the nation was banned from the next global cup four years later - poor results, and the COVID pandemic.
But the world No.9 ranked outfit flexed their collective muscle against the world No.49 Uzbeks, who not only lost the game but also lost their first-choice goalkeeper to injury.
Shot-stopper Maftuna Jonimqulova was stretchered from the field with a neck injury in just the eighth minute after a teammate fell on her during a goal-mouth scramble.
By that time, the Uzbeks were already in arrears after Myong  scored the opening goal six minutes into the game.
The Korean attacker fired a sweetly-timed right-footer into the net when a rebound fell to her about seven metres from goal.
Myong scored again from the penalty spot in the 21st minute after her teammate Chae Un Yong was shoved in the back and felled by Uzbekistan's Zarina Mamatkarimova.
And in the 41st minute, the Korean completed her hat-trick with another penalty after a Uzbek handball in the box; Myong repeated her initial spot-kick, again shooting into the low left corner of the net.
The Uzbeks showed greater defensive steel in the second half but never threatened in attack - they managed one shot on goal in the match; the Koreans had 28.
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