Cathay Pacific has promised to honour first and business-class flights accidentally sold for a fraction of their value.
A ticketing error meant flights from Vietnam to the United States and Canada which would usually cost around $16,000 (£12,700) for as little as $670 (£530) on New Year's Day.
The airline acknowledged the error on Wednesday, tweeting that those who had bought tickets in the "VERY good surprise 'special'" would be welcomed on board, using the hashtags #promisemadepromisekept and #lessonlearnt.
A first class round trip from Vietnam to the US would usually cost around $16,000, while business class flights range from $4,000 to $6,000.
A Cathay spokesperson declined to say how many tickets were sold at the discounted price.
Travel blogger Wang Guanran, told AFP he was working in the early hours of New Year's Day when he spotted websites alerting people to the cheap flights around 5am Hong Kong time.
He said he managed to snap up five first class round trips from Vietnam to New York for $840 each and a business class flight for $699.
It is not the first time airlines have sold cheap fares by mistake.
In 2014, Singapore Airlines agreed to honour around 400 business class flights to Australia which had been sold at economy prices.
Last year Hong Kong Airlines said it would do the same after a similar mistake was made.
Air Canada is involved in a lawsuit for refusing to honour a pricing mistake in 2015.