Naomi Watts (search) ran rings around the competition at movie theaters.

Watts' horror sequel "The Ring 2" (search) debuted as the top weekend movie with $36 million, more than double the $15 million opening gross of the original film, a surprise horror hit in 2002.

"Robots," (search) the previous weekend's No. 1 movie, slipped to second place with $21.8 million, lifting its 10-day total to $66.9 million, according to studio estimates Sunday.

Disney's family hit "The Pacifier" held up well in third place with $12.5 million, pushing its three-week total to $72.3 million.

With "Robots" and "The Pacifier" remaining strong draws, Disney's new family movie "Ice Princess" had a tough time finding a toehold in the market. "Ice Princess," starring Michelle Trachtenberg, premiered at No. 4 with $7 million.

In "The Ring 2," Watts reprises her role as a journalist and single mom trying to save herself and her son from the curse of a killer videotape, whose viewers die horrible deaths within a week.

The original, based on a Japanese hit, became a word-of-mouth sleeper success, holding strongly week after week as it climbed to a $129 million total domestic gross. The sequel more likely will mirror the pattern of other horror hits, which tend to open hugely then take steeper drops since so many people already have seen the movie.

"Sequels just don't play the same way. You have to expect a good drop," said Jim Tharp, head of distribution for DreamWorks, which released both "Ring" flicks. "Obviously, we would hope to get that $100 million club, but we don't do any of those projections this early in the game."

"Ice Princess" features Trachtenberg as a science geek who abandons the physics classroom to pursue a new dream as a figure skater.

Disney benefited by exceeding industry expectations on "The Pacifier," but that film may have wound up siphoning off some of the family crowd that might have caught "Ice Princess."

On the plus side, trailers for "Ice Princess" ran before "The Pacifier," so audiences who caught that movie may be encouraged to see "Ice Princess" during spring break over the Easter holiday, said Chuck Viane, Disney head of distribution.

"It's a double-edged sword. It helps you and it hurts you a little," Viane said.

Woody Allen's "Melinda and Melinda" — which stars Radha Mitchell in dual roles in a comic and tragic retelling of the same story — opened strongly with $74,048 on three screens at one New York City theater.

The film, which co-stars Will Ferrell, Chloe Sevigny and Amanda Peet, gradually expands into nationwide release through April 8.

Estimated ticket sales for Friday through Sunday at North American theaters, according to Exhibitor Relations Co. Inc. Final figures will be released Monday.

1. "The Ring 2," $36 million.

2. "Robots," $21.8 million.

3. "The Pacifier," $12.5 million.

4. "Ice Princess," $7 million.

5. "Hitch," $6.6 million.

6. "Be Cool," $5.8 million.

7. "Hostage," $5.797 million.

8. "Million Dollar Baby," $4.1 million.

9. "Diary of a Mad Black Woman," $3.5 million.

10. "Constantine," $2.3 million.