The Irish boyband garnered more sales for The Love Album than U2 did for their best of compilation U218, which took second place.
Following closely behind were The Beatles, while Oasis' much-anticipated best of Stop The Clocks only entered at number five.
Disappointingly, The Corrs' greatest hits didn't manage to hit the top 40, only coming in at 43.
The results of the bigger-scale UK race, meanwhile, are revealed on Sunday. Early indications show that Westlife are likely to take the lead there also.