Samsung's new flagship handset is struggling to compete with its aging (relatively speaking) iPhone rivals.
The Galaxy S5 only managed to secure the third spot in terms of the best-selling smartphone in the UK in May, falling behind the iPhone 5S and iPhone 5C which snagged the top two positions.
This is according to Kantar Worldpanel ComTech's stats, with May being the first full month the S5 was on sale. The figures will be disappointing news for Samsung, but not surprising given last week's admission that the S5 hadn't got off to as much of a blistering start as reports first indicated.
The bright spot for Samsung is that of those who did buy the S5 across major Euro markets, 17 per cent switched from an iPhone, so everything isn't going Apple's way.
Dominic Sunnebo, strategic insight director at Kantar, commented: "The Samsung Galaxy S5 has had some success in attracting former iPhone owners across Europe. In general, consumers buying the Galaxy S5 were primarily attracted by its large screen size. This is something Apple is likely to address with the rumoured larger screen iPhone 6 launch expected in late September."
The latest from Uswitch.com's mobile tracker reflects these Kantar figures, with the iPhone 5S leading from the iPhone 5C, and the Galaxy S5 in third, followed by its predecessor the S4.
According to Kantar, Android, of course, remains the biggest OS by far with a 73 per cent market share compared to 16 per cent for iOS and 8 per cent for Windows Phone.