LOS ANGELES (REUTERS)- These are the weekends that record-breaking summers are made of.

The North American box office sizzled as Disney and Pixar's Inside Out and Universal's Jurassic World duked it out at the multiplexes. After shattering records for domestic and international debuts, Jurassic World became only the second film in history to top US$100 million (S$133 million) in two separate weekends.

The dinosaur sequel nabbed first place with a massive US$102 million, pushing its domestic total to US$398.2 million. Jurassic World has now passed Jurassic Park (US$357.1 million) as the highest-grossing domestic release in the franchise's history when not adjusted for inflation.

Its dominance ended one of the most remarkable winning streaks in cinema history, putting a period to Pixar's run of first place finishes. Every previous film released by the studio bowed in the top spot on domestic charts.

Not that Disney is complaining. Buoyed by rapturous critical notices, Inside Out scored the second best debut ever for Pixar, behind only Toy Story 3's $110.3 million opening, and the highest opening weekend ever for an original, non-sequel property, passing Avatar's US$77 million start.

The brainy family film picked up US$91 million from 3,946 playdates. That was a significant jump on the US$60 million-plus opening that Disney had projected for Inside Out.

Inside Out, which unfolds largely inside the mind of a young girl struggling to come to terms with her family's move to San Francisco, represented a big gamble for Pixar. Produced for US$175 million, it had a concept that defied an easy sales pitch and could have gone soaring over the heads of younger moviegoers.

Instead, critics praised the film as ranking alongside such previous Pixar greats as Up and Wall-E in pairing cinematic daring with emotional uplift.

Disney's distribution chief Dave Hollis praised the studio's marketing team for conveying the twisty concept in a series of upbeat ads and for getting the word out early that the picture was not to be missed.

Inside Out first screened for movie theatre owners and press at CinemaCon in April and followed that up with a high-profile premiere at the Cannes Film Festival.

"There was a critical mass building of people saying 'wow it's so original, it's Pixar doing what Pixar does best,'" said Hollis. "That critical mass tipped over into the consumer mindset."

Analysts argue that the positive response was one of the major reasons "Inside Out," like Jurassic World before it, soared past projections.

"This is another example of word of mouth spreading fast for a movie and people getting behind in a big way," said Phil Contrino, vice president and chief analyst at BoxOffice.com.

It wasn't just reviews. Production delays on Pixar's The Good Dinosaur forced that movie to abandon its original 2014 release date, putting a two-year gap between the animation studio's films and driving interest in its latest title.

"It speaks to the power of Pixar," said Jeff Bock, an analyst with Exhibitor Relations. "Audiences see that name and they know it stands for quality. You can't say that about any other company that does animation. They're more hit and miss."

Opening weekend crowds for Inside Out were 56 per cent female and 38 per cent under the age of 12. Families comprised 71 per cent of the audience.

There was one casualty at the box office. Open Road's Dope did not perform as well as the studio had hoped. The Sundance Film Festival favourite sparked a bidding war when it debuted in Park City, but the picture's off-beat sensibility (it's a comedy about nerds living in South Central), was difficult to convey to audiences.

Dope pulled in a disappointing US$6 million from 2,002 locations, good enough for a fifth place finish.

Open Road Chief Marketing Officer Jason Cassidy noted that the film played well with critics and audiences, which could help it "leg it out" in coming weeks.

"When you have two movies doing almost US$200 million in the marketplace, it's tough for much else to cut through," said Cassidy. "The great news is we have a great movie that plays great."

In third place, Fox's Spy showed some staying power, slipping 29 per cent in its third weekend to US$10.5 million and bringing its stateside total to US$74.4 million.

Disaster film San Andreas nabbed the fourth position on charts after snagging US$8.2 million and pushing its domestic haul to US$132.2 million.

Among art house releases, new indie distributor The Orchard kicked off the sex comedy The Overnight to an estimated US$61,523 this weekend on three screens in New York and Los Angeles, for a per-screen average of US$20,507.

In its second weekend, Me and Earl and the Dying Girl expanded from 15 locations to 68 theatres, bringing in US$351,678. The dramedy about a young cinephile who befriends his critically ill high school classmate has earned US$645,090 so far.

Final numbers have yet to be calculated, but the overall box office will annihilate the figures put up a year ago when Think Like a Man Too and Jersey Boys"opened.

"This is an example of the market expanding when it needs to accommodate two big movies," said Contrino.