LOS ANGELES — Jeff Bridges’ sci-fi sequel “Tron: Legacy” has leaped to the top of the box-office grid with a $43.6 million opening weekend, according to studio estimates Sunday.

The Disney release reboots the story line started in Bridges’ 1982 tale “Tron,” in which his character is hurtled into a deadly virtual reality known as the Grid. The movie co-stars Garrett Hedlund and Olivia Wilde.

Though quaint by today’s standards, the computer-graphic effects in the original “Tron” were cutting-edge at the time. Yet the movie was a box-office underachiever whose following somehow swelled in the intervening decades in a way that perplexed even the studio’s executives.

“I sure wish I knew, because there is a very, very committed core group of people who just love that movie, and they have fanned the opening-weekend grosses,” said Chuck Viane, head of distribution for Disney.

Other newcomers premiered with modest to poor receipts, continuing a sluggish end to Hollywood’s year.

The weekend proved no picnic for Dan Aykroyd’s family flick “Yogi Bear,” which fell flat at a weak No. 2 with $16.7 million. The Warner Bros. release features the voices of Aykroyd and Justin Timberlake in an adaptation of the TV cartoon about the picnic-basket-thieving bear.

With children out of school over the holidays, Warner Bros. executives hope “Yogi Bear” will hold up well through Christmas and New Year’s.

By The Associated Press