Apple is getting closer to matching Samsung Electronics on its home turf, as it has done with other East Asian rivals.
Apple had a record-high 20 percent of the South Korean smartphone market in the last quarter of 2014, up from 11 percent a year earlier, according to Strategy Analytics.
It's an embarrassing development for Samsung, which has seen its mobile fortunes wither since the release of the iPhone 6.
"The South Korean market is seeing a changing of the guard," Strategy Analytics analyst Neil Mawston said via email. "Apple is outperforming in East Asian markets because of enhanced new smartphone models, deeper distribution channels and large subsidies from mobile operators."
According to Counterpoint Research, Samsung's domestic market share in smartphones fell to 46 percent in November from 61 percent in September, while Apple rose to 33 percent from 7 percent.
"Advanced consumers in markets such as Japan, China and Korea have over the last two years warmed up to larger-screen smartphones. Most consumers in these markets are mature smartphone users and have been waiting for a larger-screen iPhone," said Neil Shah, a partner at Counterpoint.
"There has been a huge pent-up demand for large screen iPhones and as a result Apple has been able to extend its lead handsomely."
Samsung will take little comfort from Apple's performance next door. In China, Apple recently grabbed the lead in the smartphone market for the first time, according to Canalys, due to the popularity of the iPhone 6 and 6 Plus. In Japan, it has been dominant since 2012, according to MM Research Institute, which puts Apple's share at 57 percent during the April to September period of 2014, more than Sharp and Sony combined.
Even on the world stage, Apple's blockbuster sales of 74.5 million iPhones in the last quarter have put it neck and neck with Samsung.
Tim Hornyak covers Japan and emerging technologies for The IDG News Service. Follow Tim on Twitter at @robotopia.