Apple began selling its latest iPhone in China today, nearly a month after other major countries due to a licence delay by regulators.
But it faces a tough battle with rivals led by Samsung in the crucial market.
The new gadget hits shelves in China a day after the tech giant unveiled a new line-up of iPads in the US in a bid to face off tough competition in the cooling tablet market.
Apple's products enjoy a devoted following in China, the world's second-largest economy and the largest smartphone market according to an industry estimate.
t launched the large-screen iPhone 6 and iPhone 6 Plus in 10 countries and regions on September 19, but could not do so in mainland China because it lacked a key network access licence.
Chinese media have reported widespread smuggling of the new phone into China given its initial unavailability.
The Ministry of Industry and Information Technology granted permission late last month, but said it had pressed Apple to improve personal data security to gain approval and quoted the US firm as saying it would do so.
Apple is only in sixth place in China's highly fragmented smartphone market, where cheaper phones using the Android operating system are popular.
Apple has a 6.9% share, according to consultancy Analysys International, far behind leader Samsung of South Korea, which has 15.4%.
Analysts said the new models' larger screen would appeal to Chinese consumers and the launch should help Apple's sales, despite their high prices.
The iPhone 6 with 16 GB of memory is selling for the equivalent of $867 in China, significantly higher than neighbouring Hong Kong where the same model retails for $726. The top-end iPhone 6 Plus with 128 GB sells for $1,277 in the mainland.