The firm said it sold 41.3 million iPhones in the three months to the end of June, up just 1% from last year.
But the average iPhone selling price hit $724, well above the expected $694.
The firm said its $999 iPhone X - launched last year - remained its most popular iPhone model in the quarter and had driven the higher sales price.
Strong revenue growth of 31% from Apple's services business, which includes the App store, Apple Music and Apple Pay, also boosted its performance.
The services business is on track for more than $14bn in revenue in 2020, chief executive Tim Cook said.
Overall the tech giant's revenue jumped 17% year-on-year to a quarterly record of $53.3bn (£40.6bn), with every region except Japan reporting double digit growth.
Profits rose to $11.5bn, up 32% compared to the same period in 2017.
Shares in the Californian tech giant jumped more than 3% in after hours trading in New York.
The gains brought Apple, already the world's most valuable company, one step closer to a market value of $1 trillion.
"The lesson Apple's management has learned from the iPhone X, is when you sell a smartphone for more than $1,000 you can sell fewer units and still reap the financial benefits," said analyst Thomas Forte from DA Davidson & Co.
Executives said they are confident about Apple's position. The firm forecast revenue in the range of $60bn to $62bn in the July to September period, indicating a fifth consecutive quarter of double digit growth.
Chief executive Tim Cook also downplayed concerns about how trade tensions between the US and China might affect Apple's business.
He said the firm had not been affected directly by the tariffs in place so far. It is still reviewing the implications of threatened tariffs on a proposed $200bn in Chinese goods, he added.
"Our view on tariffs is that they show up as a tax on the consumer and wind up resulting in lower economic growth and sometimes can bring about significant risk of unintended consequences," he said.
However, he said he was optimistic that "this will get sorted out".