Apple can rejoice in the success of its flagship iPhone 5S smartphone as it ranked the best selling smartphone in May, defeating Samsung in the long-running battle.

The smartphone battle continues to intensify as tech leaders Apple and Samsung fight for dominance in the lucrative business. The Cupertino tech giant took the lead in sales of its iPhone 5S smartphone in the month of May, 2014, pushing Samsung's flagship Galaxy S5 to the second position. The list of top 10 bestselling smartphones for the month of May was compiled by market research firm Counterpoint.

According to the statistics, Samsung dominated the top 10 list of best selling smartphones with five of its flagship devices. Following the Galaxy S5, Samsung's 2013 flagship phone Galaxy S4 and Galaxy Note 3 came in third and fourth. Apple's iPhone 5C and 4S managed to secure a place in the top 10 list, at fifth and sixth position, but the iPhone 5C sales continue to decline, the report said.

"iPhone 5c shipments continue to decline, but Apple continued clearing excess inventory for the [smartphone] during the month," according to Counterpoint's press release, Monday.

In addition to Apple and Samsung, Chinese smartphone maker Xiaomi made it to the top 10 smartphone list. The phone maker's MI3 and Hongmi Redrice models secured seventh and ninth places, respectively. The Xiaomi MI3 sold better than Samsung Galaxy S4 mini, while the Hongmi Redrice beat Galaxy Grand 2 in global sales.

Counterpoint suggests big-screen smartphones, popularly termed as "phablets," are gaining traction in the mobile industry. The research firm is optimistic about Apple's rumored iPhone 6, which is expected to feature a 5.5-inch screen. According to the report, 40 percent of the smartphones sold in May were phablets.

Looking beyond the top 10 smartphone list, Sony's Xperia Z1 along with Moto G, Huawei Honor 3C and LG G2 made it to the top 20. Unfortunately, none of Nokia or Windows Phone devices were a part of Counterpoint's top 10 bestsellers in May. But Nokia X smartphones are likely to make it to the list in June's sales report.