The tech giant's strategy of charging more for its phones has paid off, with revenues jumping in the last three months despite relatively flat sales.
Revenues rose 20% to $62.9bn year-on-year, and profits rose 31% to $14.1bn.
But a warning of possible weaker sales in coming months sparked a share price slide after official trading ended.
The sell-off accelerated after Apple said it would stop disclosing the number of units sold.
Apple executives defended their decision, arguing that the figures are no longer good indicators of the firm's financial health.
Analysts, however, warned that outsiders may view it as a move that masks less sunny performance.
The total number of smartphones sold by all makers globally declined for the first time in 2017.