Cameron conceived Avatar before he made Titanic
Sci-fi epic Avatar has topped the North American box office, taking $73m (£45.3m) on its opening weekend.
James Cameron's much-hyped 3D film also took an estimated $232.2m (£144.1m) worldwide - the ninth biggest opening to date, 20th Century Fox said.
Disney's The Princess and the Frog slipped to second, with $12.2m (£7.6m).
Drama The Blind Side dropped to three while the Hugh Grant and Sarah Jessica Parker romantic comedy Did You Hear About the Morgans? came in at four.
NORTH AMERICAN BOX OFFICE
1. Avatar - $73m
2. The Princess and the Frog - $12.2m
3. The Blind Side - $10m
4. Did You Hear About the Morgans? - $7m
5. The Twilight Saga: New Moon - $4.4m
The top five was rounded off by The Twilight Saga: New Moon.
Avatar - set in the 22nd Century on a distant planet, Pandora, inhabited by a humanoid race - reportedly cost up to $400m (£248.2m) to make and market.
20th Century Fox's head of distribution, Chris Aronson, said there was "no question" the studio had made a good investment.
"The word of mouth is something that I don't know I've ever seen in this business before," he said.
Paul Dergarabedian, box office analyst for Hollywood.com, said: "What they spent on this movie was totally justified and they're going to more than earn it back."
Avatar's weekend haul was the sixth biggest of the year in the US and Canada.
The record for 2009 was set last month by The Twilight Saga: New Moon while the biggest opening weekend of all time in North America was $158m (£98m) for last year's The Dark Knight.