"Oh my goodness this is an wonderful fare", he wrote, but he warned travelers to wait a few days after booking to make additional non-refundable plans.
Cathay Pacific Airlines is doing the noble thing and owning up to the mistake, which saw tickets for the Business Class journey priced at $675 rather than its usual $16,000 price.
Return fares in the premium cabin from Da Nang to NY started at US$675 (S$922) for travel in August, Mr Gary Leff, a travel and loyalty programme blogger on View from the Wing, wrote on Monday (Dec 31).
Cathay Pacific has announced it will honour its "mistake" after it sold tickets worth an estimated $US16,000 for just $US675 to surprised customers.
"We do not want to go back on our promise to our customers", Cathay said on its Twitter account.
While the passengers were kept happy, the mistake adds to the embarrassments for the carrier that's struggling to turn its fortunes around while competition intensifies from Chinese and budget airlines.
The offer for the cheap business class tickets lit up the internet in the new year with frequent fliers and bargain hunters alike buying tickets quickly as word spread across social media and popular flight blogging websites and forums.
While rare, it is not the first time a pricing error like this has happened to an airline.
In October, Cathay Pacific acknowledged hat its computer system had been compromised, exposing the personal information and travel histories of up to 9.4 million passengers.
Cathay had sold tickets to the US and other destinations from Vietnam in a promotional offer that ended December 31, according to its website.
The next day, another travel website The Points Guy reported seeing business class flights from Danang to NY selling for less than US$700 - "cheaper than a coach ticket".