Organisers of the 2008 Beijing Olympics have suspended ticket sales until Monday, after their booking system crashed due to high demand on Tuesday.
Eager customers queued up at bank branches around the country
In a statement, the organising committee apologised, saying the ticket centre had underestimated demand.
In the first hour after sales opened, the ticket website received more than 200,000 ticket requests per second.
Customers eager to buy the first-come, first-served tickets also jammed phone lines and queued at designated banks.
A lottery in June allocated the first round of 1.6m tickets to be made available for next year's games.
But the opening of this second round, in which 1.8m tickets are up for grabs, has now been suspended until Monday for technical work to the ticket sales system.
"We sincerely apologise to the public," said the organising committee in a statement.
China would like to stage the "perfect" Olympic Games
"Demand was much higher than the ticket centre estimated and flaws existed in preparation work that caused inconveniences for applicants," the statement said.
The ticketing website received more than 8m visits in the first hour, while at least 2m people called the telephone hotline.
Huge queues formed outside designated Bank of China branches, with some customers starting to queue hours before the branches opened.
But only 9,000 tickets were reported to have been sold in the first two hours.
China will eventually sell about 7m tickets to the games in three phases, with about three-quarters going to residents of China and the rest to overseas buyers.
China wants to stage the perfect Olympic Games and would like every seat filled with cheering, patriotic supporters, say correspondents.
Organisers warned that people hoping to see the most popular events, including gymnastics, table tennis and the opening and closing ceremonies, may be disappointed.