LOS ANGELES, March 25 (Xinhua) -- The ninja turtles mutated into box office winners in North American theaters this weekend, toppling the two-week dominance by ancient Spartan warriors from the battle epic "300," according to preliminary box office figures released here Sunday.

"TMNT," an animated update of the "Teenage Mutant Ninja Turtles" movies and cartoons, brought in an estimated 25.5 million dollars in their box office debut over the weekend, said Los Angeles-base box office tracker Media By Numbers.

The Persian war epic "300" slipped to second place after two weeks at the top, bringing in about 20.5 million dollar in the three-day period. The film has raked in a staggering 162.4 million dollars in North America in just three weeks since its release.

Both "300" and "TMNT" are Warner Bros. movies, and final box office figures for the Friday-to-Monday period will be released Monday.

Paramount's "Shooter," starring Oscar-nominated Mark Wahlberg as a former U.S. Marines sniper who is framed for assassinating the president, debuted in third place with about 14.5 million dollars, closely followed by Disney road trip comedy "Wild Hogs" with about 14.4 million dollars.

Another new release, New Line's "The Last Mimzy" about two children who find a box of toys that gives them superpowers, debuted in fifth place with an estimated 10.2 million dollar.

The weekend's top 12 films in North America posted a combined gross of almost 126 million dollars, up 28.5 percent over the same weekend last year. Ticket sales for the top 12 films were up nearly 20 percent compared with last weekend.