Despite the launch of new S6 models, Samsung's premium phones continued to be challenged by Apple's large-screen iPhones. Samsung lost 4.3 percentage points in market share and declined 5.3 percent in unit sales in the second quarter of 2015. Huawei recorded the highest sales growth rate of 46.3 percent, thanks to strong overseas sales and 4G smartphone sales in China. iPhone sales increased 36 percent, which helped Apple gain 2.4 percentage points in market share. Apple recorded strong iPhone replacements in both emerging and mature markets — and particularly in China. Total iPhone sales in China grew 68 percent to 11.9 million units.