MELBOURNE (AFP) - While Asian Cup fever may not quite be sweeping Australia as it competes with tennis and cricket, record numbers of armchair fans are tuning in across the region.

Tournament organisers, who released the figures on Thursday, added that the Asian Cup's official Twitter feed has reached more than 1.82 billion users, making it one of the most talked-about football events ever in Asia.

TV ratings across China, Japan and South Korea have hit new highs for the Asian Cup with more than 52 million Chinese viewers catching at least some of last week's victory over North Korea on state broadcaster CCTV - more than twice the population of Australia.

Those figures scored the highest audience before Chinese prime time since January 2013, when tennis star Li Na competed in the final of the Australian Open.

TV audiences in China have risen steadily as the team built momentum, topping Group B with three successive wins.

Cumulative average viewership, or the number of people watching at any given time, after China's first two matches was higher than for all three of their games at the 2011 Asian Cup in Qatar.

Ratings are expected to skyrocket for China's blockbuster quarter-final against hosts Australia, which is being played later on Thursday.

Just under 50 million Japanese tuned in to watch the defending champions play their three group games while South Korea's 1-0 win over the Socceroos at the weekend attracted a peak of more than 11 million, a whopping 23 per cent of the population.

Meanwhile, the number of fans turning up to cheer their teams at the five venues in Australia reached 395,892 after the group stages which ended on Tuesday, organisers said.