The Witcher 3: Wild Hunt is the biggest release of the year so far and the latest game to top the all-format weekly chart.
The Witcher 3 outperformed the year's previous biggest-selling week one title, Battlefield Hardline, by 53%, and has sold 608% more week one copies than its 2012 predecessor.
The Witcher 3 sold 63% of all its copies on PS4, compared to 32% on Xbox One and only 5% on PC.
It is followed by Farming Simulator 15 in second, which re-enters the chart after launching on PS4, PS3, Xbox One and Xbox 360.
With 5 million UK sales, GTA 5 remains in third, followed by a resurgent FIFA 15 at four and Project Cars at five.
Wolfenstein: The Old Blood, Battlefield Hardline and Mortal Kombat X follow at six, seven and eight, while Call of Duty: Advance Warfare and Destiny complete the top ten.
The top 20 in full: 1. (-) The Witcher 3: Wild Hunt (Bandai Namco) 2. (-) Farming Simulator 15 (Koch Media) 3. (3) Grand Theft Auto 5 (Rockstar) 4. (6) FIFA 15 (EA Sports) 5. (1) Project Cars (Namco Bandai) 6. (2) Wolfenstein: The Old Blood (Bethesda) 7. (10) Battlefield Hardline (Electronic Arts) 8. (4) Mortal Kombat X (Warner Bros) 9. (7) Call of Duty: Advanced Warfare (Activision) 10. (9) Destiny (Activision) 11. (-) Bloodborne (Sony) 12. (8) Dying Light (Warner Bros) 13. (11) Minecraft: Xbox Edition (Microsoft) 14. (13) Minecraft: PlayStation Edition (Sony) 15. (5) Final Fantasy X / X-2 HD Remaster (Square Enix) 16. (15) WWE 2K15 (2K Sports) 17. (16) Terraria (505 Games) 18. (20) Far Cry 4 (Ubisoft) 19. (12) Halo: The Master Chief Collection (Microsoft) 20. (14) Forza Horizon 2 (Microsoft)