Convincing existing users as well as feature phone users to upgrade to new smartphones will now be the key to further growth in the China market, Fok said.
Apple was the top smartphone vendor in the mainland in the first quarter, snagging a 14.7 percent market share, ahead of rivals Xiaomi, Huawei and Samsung, which had a 13.7 percent, 11.4 percent and 9.7 percent share, respectively.
"Xiaomi slipped to the second position as it faced strong competition from other vendors in the low to mid-range segment of the market, while Huawei maintained third position as it saw a good uptake in the mid-range segment," IDC said.
"Samsung and Lenovo both led the market at least once last year, but rankings have since changed quickly, highlighting the volatility of consumers' brand preference in China," it said. Lenovo, in fifth place, had an 8.3 percent share of the market.
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With China's appetite for smartphones beginning to cool, local smartphone vendors will need to step up their presence in India as well as more Southeast Asian countries for fresh growth opportunities.
"To successfully combat local players overseas, Chinese vendors will need to focus on channel relationships and localized marketing strategies," said Tay Xiaohan, senior market analyst, client devices team at IDC Asia/Pacific.
"Most of the market's growth will come from sub-$150 phones as feature phone users switch to low-cost smartphones."
Xiaomi has been leading the way with its expansion outside China, launching in Asian markets including Singapore, India and Indonesia last year. This year, the company will begin selling headphones, smart wristbands and accessories online in the U.S., taking its first tentative step onto Apple's home turf.