World of Warcraft: Cataclysm has become "the fastest-selling PC game of all time", according to internal figures from publisher Activision Blizzard.
The latest WoW expansion pack hit "a record 3.3 million copies sold through" in its first 24 hours of availability, the company said today.
The milestone eclipses the previous record of more than 2.8 million copies sold in 24 hours, set in November 2008 by Blizzard's second WoW expansion, Wrath of the Lich King.
"We had to bring Azeroth to the brink of destruction in Cataclysm, but the result was our best expansion yet," said Blizzard CEO Mike Morhaime.
"We want to thank all of our new, existing, and returning players throughout the world for their incredible enthusiasm and support, and we look forward to hearing what they think about all the new content."