LOS ANGELES (AP):

Pixar Animation remains undefeated at the box-office races.

The Disney unit's animated sequel Cars 2 cruised to a No. 1 finish with a US$68-million opening weekend, according to studio estimates yesterday. That makes 12 wins in a row for Pixar since the company's first feature film, 1995s Toy Story.

"It couldn't be any better than that. What an unbelievable track record these guys have," said Chuck Viane, head of distribution for Disney.

Cars 2 added US$42.9 million in 18 overseas markets, giving it a worldwide total of US$110.9 million.

Domestically, Cars 2 nearly matched the US$68.1-million debut of Disney-Pixar's Up two years ago, though it was well below the company's record of US$110.3 million for last year's Toy Story 3.

The original Cars had a US$60.1-million debut in 2006, but factoring in today's higher admission prices, it sold more tickets than Cars 2.

Premiering in second-place was Cameron Diaz's classroom comedy Bad Teacher with US$31 million. The Sony Pictures release added US$12.9 million overseas in about 10 countries.

The previous weekend's No. 1 flick, Ryan Reynolds' Green Lantern, fell to third-place with US$18.4 million. That was off a steep 65 per cent from its revenues over opening weekend, raising the domestic total for the Warner Bros. superhero tale to US$89.3 million.

Both new wide releases came in ahead of industry projections, which had pegged Cars 2 at an opening of around US$60 million and Bad Teacher at about US$25 million.

Cars 2 features Owen Wilson and Larry the Cable Guy reprising their voice roles for race car Lightning McQueen and tow truck Mater as the two are caught up in a spy adventure during an international racing tour.

The movie overcame unusually harsh reviews for Pixar, whose films include such critical darlings as Ratatouille, Finding Nemo, The Incredibles and WALL-E.

Disney's Viane said audiences gave Cars 2 top grades in exit surveys, a sign that the movie should have a long life at theatres like previous Pixar flicks.

While the G-rated Cars 2 cornered the family market, Bad Teacher was the weekend's grown-up choice, starring Diaz as a foul-mouthed, boozy, gold-digging educator.

"She just went with it with great abandonment. She totally just let it go," said Rory Bruer, head of distribution for Sony.

While women accounted for 63 per cent of the audience for Bad Teacher, Sony executives hope word-of-mouth over Diaz's brazen performance will draw more men to see it in the coming weeks.

The upcoming fourth of July weekend looks huge as Paramount's sci-fi sequel Transformers: Dark of the Moon blows into IMAX theatres tomorrow night and general cinemas Wednesday.

That will be followed in mid-July by the Warner Bros fantasy finale Harry Potter and the Deathly Hallows: Part 2.

"With Cars 2 and the one-two punch of Transformers and Harry Potter, I think we have a shot at knocking that revenue deficit down to the break-even point or even pulling a little bit ahead of last year," said Hollywood.com analyst Paul Dergarabedian.