Tournament organisers also addressed concerns as to why the apparently sell-out must-win final group game between the hosts and Kuwait at the 40,000 capacity Khalifa Stadium yesterday saw many seats unoccupied.
That same evening, only 3,529 people were at Al Gharafa Stadium -- capacity 22,000 -- to see a thrilling 2-2 draw between China, the world's most populous country, and Uzbekistan.
The result saw the Uzbeks top their group and China go home, while Qatar also progressed to the last eight with a 3-0 win.
"We try our best to attract people to come here," said tournament director Tokuaki Suzuki, adding it was particularly hard to draw large crowds to stadiums when there are two games going on at the same time.
"There are not so many people who came to Qatar from China," he said. "We are trying our best to attract fans to the stadiums."
Qatar, which is smaller than the Pacific island of Vanuatu or the American state of Connecticut, controversially won the right to host the World Cup in 2022 ahead of Australia, Japan, South Korea and the United States.
Iran coach Afshin Ghotbi has been among those who has pleaded with local people to fill stadiums at the Asian Cup, warning: "The world is watching."
But his call has gone largely unheeded, with stadiums usually about half-full. Organisers were also left embarrassed after Qatar fans left in their droves well before the end of the hosts' opening 2-0 defeat to Uzbekistan.
The cavernous Khalifa Stadium was eerily empty by the time the final whistle blew, the celebrations of the Uzbeks' small travelling contingent echoing around the ground.
Jassim Al Rumaihi, spokesman for the local organising committee, admitted he was "shocked" by the vast rows of empty seats at the China-Uzbekistan game.
"Tickets go to the corporate companies, but unfortunately some people don't come," he said.
"I was shocked because 8,000 tickets were sold at Al Gharafa," he added, calling it "a big gap" between the number of tickets sold and the little more than 3,500 fans actually at the stadium.
"We are making every effort to get bigger crowds, especially in the second round of games, I hope."
Of the game involving the World Cup hosts Sunday, where there was an official crowd of 28,339, leaving about 12,000 seats vacant, he said: "We saw a lot of empty seats at the match. Some people buy tickets, but they don't come.
"In future we decided that each person is allowed to buy 10 tickets only. This is one solution."
More than 400,000 tickets had been sold in total, the Qatar Tribune quoted Al Rumaihi as saying.