The X Factor winners' Damien Rice cover shot to the top of the UK singles chart on Sunday night (December 18) following its release after their show victory.
'Cannonball', which dethroned the show's 2009 runner-up Olly Murs from the number one spot, outsold the other top five entries combined.
However, reports have said that the single sold just 210,000 copies in its first week, less than half that of Matt Cardle's 2010 hit 'When You Collide', which shifted 429,000 copies during its first week of release.
Little Mix, individually known as Jesy Nelson, Perrie Edwards, Leigh-Anne Pinnock and Jade Thirlwall, triumphed over Marcus Collins at the X Factor final on December 11. The girlband have since said that they are now focusing on international success.
X Factor judge Tulisa Contostavlos has predicted that Little Mix will become "the biggest girlband [in] years".
Watch Little Mix chat to Digital Spy below: