The company sold 74.5 million iPhones in its fiscal first quarter ended December 27, while many analysts had expected fewer than 70 million. Revenue rose to $74.6 billion from $57.6 billion a year earlier.
Shares rose about 5 percent to $114.90 in after-hours trade.
Apple Chief Financial Officer Luca Maestri told Reuters in an interview that the company did not sell more iPhones in China than the United States, despite some earlier predictions by research analysts.
But revenues in China were up 70 percent in the quarter from a year earlier, in large part due to a massive bump in iPhone sales. The company's success in the competitive Chinese market can be attributed to its partnership with China Mobile, the largest global mobile carrier, and the appeal of the larger screen size of the iPhone 6 and 6 Plus.
Maestri said he does not expect Apple to struggle on account of China's slipping economic growth. Maestri said Apple "feels good" about its position in China.
"We haven't seen a slowdown," he added.
Maestri also said the company doubled iPhone sales in Singapore and Brazil.
Carolina Milanesi, an analyst with Kantar Worldpanel ComTech, also lauded a 14 percent rise in unit sales of Apple Macintosh computers and sales of older iPhone models.