The explosive growth of smartphone sales in China, the worlds biggest smartphone market, has come to a halt as unit shipments declined for the first time in more than two years, data firm IDC said on Thursday. Shipments of smartphones in China fell 4.3 percent quarter-on-quarter to 90.8 million from 94.8 million units, the first drop-off since the second quarter of 2011, according to IDC. The world has increasingly looked to China as the powerhouse to propel the worlds smartphone growth and this is the first hiccup weve seen in an otherwise stellar growth path, said Melissa Chau, a senior research manager with IDC. We are now starting to see a market that is becoming less about capturing the low-hanging fruit of first time smartphone users and moving into the more laborious process of convincing existing users why they should upgrade to this years model. Apple Incs deal with China Mobile Ltd and the countrys rollout of high-speed 4G mobile networks will encourage adoption of 4G-compatible smartphones and help shore-up growth, according to IDC.