LOS ANGELES ? Science-fiction epic "Avatar" enjoyed another stellar showing at the North American box office to finish in top spot for the fourth consecutive week, final figures showed Monday.

Oscar-winning director James Cameron's groundbreaking 3-D spectacular, which has already grossed $1.3 billion worldwide, scooped another $50.3 million, box office tracker Exhibitor Relations said.

So far the film has taken $430.8 million in North America and is on course to overtake Cameron's 1997 Academy Awards best picture winner "Titanic" as the highest-grossing film of all time.

The phenomenal success of "Avatar" left its nearest rival, "Sherlock Holmes," trailing in a distant second place with $16.58 million.

Director Guy Ritchie's high-octane take on the adventures of Sir Arthur Conan Doyle's legendary London detective, played by Robert Downey Jr, has taken $165.2 million in three weeks.

In third spot was family film "Alvin and the Chipmunks: The Squeakquel," which scored $15.56 million.

Fourth place was occupied by horror movie "Daybreakers," a new vampire thriller starring Ethan Hawke, Willem Dafoe and Sam Neill. The film took $15.1 million in its opening weekend.

Love triangle comedy "It's Complicated," starring Meryl Streep, Alec Baldwin and Steve Martin, dropped to fifth place, taking $11 million.

In sixth spot was "Leap Year," a romantic comedy starring Amy Adams and Adam Scott, which opened with $9.2 million.

Seventh place belonged to "The Blind Side," about a white couple who gave an illiterate black teen a home and a new lease on life, earning $7.5 million.

"Up in the Air," starring George Clooney in the acclaimed story of a corporate downsizer who questions his role in life, held eighth place, with $7.2 million.

Teen comedy "Youth In Revolt", starring Michael Cera, was ninth with $6.9 million. Disney's "The Princess and the Frog" rounded out the top 10 with $4.6 million.