The Open Lowry champion had five birdies and one eagle in his last round, scoring only one shot in the best round of day four.
Ormsby finished his second day in Hong Kong with a four-under 66 to stay at the top of the leaderboard.
Another birdie on the 15th suggested a strong finish, but Lowry returned the shot on the 17th before signing for a two under par round of 68.
USA big-hitter Tony Finau was also six off, shooting a tournament-best 65 but squandering a chance to close the gap on Ormsby after three birdie putts came up just short.
The Australian did not get off to the best of starts when he stumbled with an opening bogey.
"I'm very happy with myself, fair play to Wade, he's run away with it and didn't really give us a chance but I went out there and did as much as I could", Lowry said.
Finau carded a 67 in his fourth round to finish seven shots off the pace.
"Obviously a little salty taste, but that won't last".
Amateur 17-year-old Alexander Yang led the Hong Kong contingent, finishing seven under par before he will fly back to the USA, where he is based, to start the school week.
The Hong Kong Open was scheduled to be played at the start of December, but was postponed due to the social unrest affecting the city over the attempted introduction of a controversial extradition law.
The tournament was rescheduled from November because of anti-government protests.