LOS ANGELES – How to Train Your Dragon breathed a bit of box-office fire with a $43.3 million opening weekend and a No. 1 debut, according to studio estimates Sunday.

Distributed by Paramount, the DreamWorks Animation adventure came in well behind the studio’s last cartoon comedy, Monsters vs. Aliens, which opened with $59.3 million over the same weekend last year.

With strong reviews and enthusiastic responses from viewers in exit polls, DreamWorks expects How to Train Your Dragon to have more staying power than “Monsters vs. Aliens” in subsequent weekends, though.

“People just love the film, so we’re really anticipating we’ll benefit from strong word of mouth going forward,” said Anne Globe, head of marketing for DreamWorks.

How to Train Your Dragon, featuring the voices of Jay Baruchel and America Ferrera in the tale of a Viking youth who tames a fire-breathing reptile, did outperform some other recent animated movies, among them Cloudy With a Chance of Meatballs, which opened with $30.3 million last September.

Disney’s Alice in Wonderland, which had been No. 1 the previous three weekends, slipped to second place with $17.3 million. It raised its domestic total to $293.1 million and its worldwide haul to $656 million.

John Cusack’s raunchy comedy Hot Tub Time Machine had a lukewarm No. 3 debut of $13.7 million. Released by MGM, the movie features Cusack as part of a group of losers hurled back by a time-traveling hot tub to the 1980s, where they have a chance to set their lives right.

How to Train Your Dragon pulled in 68 percent of its revenue from 3-D presentation, another triumph for the digital technology that allows theatres to show movies in three dimensions.

Yet it also highlights the limits on how much 3-D traffic theatres are equipped to handle. How to Train Your Dragon took over the bulk of 3-D theatres at the expense of Disney’s Alice in Wonderland, because the roughly 4,000 screens capable of showing digital 3-D movies is not enough to handle two full wide-release films at the same time.

“There’s no question there are not enough screens yet,” said Chuck Viane, head of distribution for Disney. “People who want to seek out ‘Alice’ in 3-D may have to travel a mile or two more than they used to. … It’s competition. I’m used to it.”

After a phenomenal 15-week run, James Cameron’s blockbuster Avatar lost most of its remaining 3-D theatres to How to Train Your Dragon. The 20th Century Fox release finally fell out of the top 10, taking in $2 million to finish at No. 11, raising its domestic total to $740.4 million. Worldwide, the movie has taken in $2.7 billion.

Another new 3-D release, Warner Bros. action tale Clash of the Titans, arrives Friday. While the success of 3-D movies has driven theatre chains to speed up their conversion to systems that can project digital 3-D films, a screen shortage will remain for the near future.

“There is a limited amount of shelf space. It’s like a traffic jam at the multiplex for these 3-D movies,” said Paul Dergarabedian, box-office analyst for Hollywood.com. “It’s a high-class problem to have, but it’s still a problem.”

Films playing in 3-D have topped the box office for nine of 13 weekends this year, Dergarabedian said.

Overall revenues were down for the first time in a month. Domestic receipts totalled $127 million, off 13 percent from the same weekend last year, according to Hollywood.com.

For the year, revenues are at $2.6 billion, 8.8 percent ahead of last year.

Results for Hot Tub Time Machine came in on the low end of distributor MGM’s expectations.

“It’s not great, but it’s OK,” said Erik Lomis, head of distribution for MGM. “It had a lot of Internet buzz, so we thought it might come in a little bit higher.”

In narrower release, Sony Pictures Classics’ sex thriller Chloe opened with $1 million in 350 theatres, averaging a weak $2,863 a cinema. That compared to an average of $10,678 in 4,055 theatres for How to Train Your Dragon and $4,956 in 2,754 theatres for Hot Tub Time Machine.

Directed by Atom Egoyan, Chloe stars Julianne Moore, Liam Neeson and Amanda Seyfried in a drama about a woman who hires a prostitute to tempt her husband and find out if he’s cheating on her.

Estimated ticket sales for Friday through Sunday at U.S. and Canadian theatres, according to Hollywood.com. Final figures will be released Monday.

1. How to Train Your Dragon, $43.3 million.

2. Alice in Wonderland, $17.3 million.

3. Hot Tub Time Machine, $13.7 million.

4. The Bounty Hunter, $12.4 million.

5. Diary of a Wimpy Kid, $10 million.

6. She’s Out of My League, $3.5 million.

7. Green Zone, $3.3 million.

8. Shutter Island, $3.2 million.

9. Repo Men, $3 million.

10. Our Family Wedding, $2.2 million.