It said Samsung shipped 83.2 million smartphones worldwide and captured 24 percent market share in the quarter, down from 31 percent a year earlier but better than Apple's 18 percent.
"Samsung continued to face challenges in Asia and elsewhere, but its global performance has stabilised sufficiently well this quarter to overtake Apple and recapture first position as the world's largest smartphone vendor by volume," Strategy Analytics Executive Director Neil Mawston said in a statement.

Samsung 's share of the Chinese smartphone market fell to fourth place in the first quarter of 2015, even as it regained the global lead, according to researcher Strategy Analytics.
Chinese brand Xiaomi Inc topped the league table in the world's biggest smartphone market with 12.8 percent of the 110 million units shipped, followed closely by Apple Inc  at 12.3 percent and Huawei Technologies Co Ltd, another Chinese player, at 10.2 percent, the data showed.
Strategy Analytics declined to say how many handsets Samsung had shipped in China during the quarter, although it expected the South Korean company to return to the top three in the next one or two quarters following the launch of its flagship S6 and S6 edge models in April.
It expects Apple to surpass Xiaomi to top the China market later this year on the strength of its popular new iPhone 6 and 6 plus models. Apple on Monday reported a 71 percent increase in sales in China to $16.8 billion.