The milestone coincided with the release of the iPhone 13, and amid otherwise stagnant demand for handsets as chief rival Huawei Technologies Co Ltd's market share declined.
Apple's smartphone market share reached 23%, a record for the brand. Its unit sales volume grew 32% year-on-year in the quarter, while total smartphone sales in China fell 9%, according to Counterpoint.
Counterpoint analyst Mengmeng Zhangcited a lower starting price in China and the impact of US sanctions against Huawei, Apple's main competitor in the high-end segment, as factors.
Apple last ranked as China's top-selling smartphone brand in late 2015, just after the company launched its iPhone 6, which attracted Chinese consumers with their large screens.
In 2021 as a whole, Apple ranked as China's third best-selling smartphone brand with 16% of the market.
Vivo and Oppo, two Android handset brands under the privately-owned BBK Electronics, ranked first and second with 22% and 21% respectively.
Year on year, Apple's unit sales rose 47% while Huawei's tumbled 68%. Overall smartphone sales in China fell 2%, according to Counterpoint.
Lengthening upgrade cycles have presented an ongoing dilemma for Chinese smartphone brands looking to maintain growth at home, as consumers delay purchasing new devices.
A global chip and component shortage has meanwhile rattled the entire electronics industry, affecting pricing and margins for all hardware makers.