Upstart Xiaomi was the top smartphone company in China last year with a 12.5 percent market share, narrowly outpacing South Korea's Samsung, market intelligence firm International Data Corporation (IDC) said Tuesday.

Samsung was just behind with 12.1 percent market share based on shipments by vendor in 2014, slipping from 18.7 percent in 2013, IDC said in a statement.

Xiaomi, founded in 2010, has excelled in China's cut-throat smartphone market by delivering high-performance products at cheap prices -- and more than doubling its market share from just 5.3 percent in 2013, according to IDC.

"Xiaomi's focus on selling low-cost phones with decent specifications, as well as the hype that it created through its flash sales, helped it to obtain the top position," IDC said.

But critics say the firm has simply copied the look of Apple's iPhones.

Xiaomi claims sales of more than 61 million smartphones last year, up 227 percent from 2013.

Xiaomi could not be reached for comment on Tuesday, the day before a week-long public holiday in China.

US technology giant Apple did not even place in the top five for market share in China for all of 2014, according to IDC.

However, it took second with a 12.3 percent share in the fourth quarter of last year -- behind Xiaomi's 13.7 percent -- helped by the launch of its large-screen iPhone 6 and iPhone 6 Plus.

"Apple had a jump to the second position in 2014 Q4 (the fourth quarter) as its iPhone 6 and 6 Plus models were only launched in China in the last quarter of the year," IDC said.

Smartphone shipments for China by all vendors reached 420.7 million units in 2014, IDC figures showed.

Apple said in January that its previous quarterly profit rocketed to $18 billion on booming global sales of iPhone models, especially in China.