The biggest movie of the year hit paydirt on its first day in video stores.

Disney’s “Pirates of the Caribbean: Dead Man’s Chest” — expected to be the biggest seller in an already busy holiday season — tallied nearly 5 million sales in its Tuesday bow, tying the March debut of Warners’ “Harry Potter and the Goblet of Fire.”

“Dead Man’s Chest,” which has earned more than $1 billion in worldwide B.O. this year, is poised to outplunder the original “Pirates” on disc. The first “Pirates” sold 11 million units during its first week on shelves in December 2003 — a record for a live-action film — and has sold 18 million copies overall, with 16 million of those on DVD.

The Mouse House has already scored a fourth-quarter hit with “Cars,” which sold around 9.5 million units its first week on shelves last month. That topped the fourth “Harry Potter” installment, which conjured nearly 9 million units its first week. Disney’s “The Chronicles of Narnia: The Lion, the Witch and the Wardrobe,” released in April, is also one of the top sellers for the year.

Studios make upward of half their annual coin during the fourth quarter, and December is especially packed with pics (Daily Variety, Nov. 21). Other top sellers include “X-Men: The Last Stand” with 5 million units its first week and “The Little Mermaid,” which sold 4 million units its first week.

“The Devil Wears Prada” and “Talladega Nights: The Ballad of Ricky Bobby” both bow Dec. 12, with “Little Miss Sunshine” arriving on shelves Dec. 19.

(Jennifer Netherby contributed to this report.)