By Lisa Richwine and Chris Michaud

LOS ANGELES/NEW YORK, Nov 10 (Reuters) - Marvel superhero Thor pounded his box office competitors over the weekend, muscling movie sequel "Thor: The Dark World" to the top of U.S. and Canadian charts with a hefty $86.1 million in debut ticket sales.

The 3D film starring Chris Hemsworth trounced last week's top movies. Raunchy comedy "Jackass Presents: Bad Grandpa" finished in second place with $11.3 million from Friday through Sunday, according to Hollywood.com.

"Free Birds," the 3D movie featuring the voices of Owen Wilson and Woody Harrelson as turkeys who team up and travel back in time to get turkey off Thanksgiving dinner plates, earned the No. 3 slot with $11.2 million, just ahead of senior citizen buddy comedy "Last Vegas" which took in $11.1 million.

"Thor: The Dark World" also hauled in $94 million from international markets, where the movie began playing on Oct. 30, distributor Walt Disney Co said. IMAX showings added another $11 million globally, and its combined global sales through Sunday reached $327 million.

The new "Thor" installment co-stars Natalie Portman as the love interest for Thor, the mighty god of thunder who battles to save his homeland of Asgard from evil forces. Tom Hiddleston plays Thor's villainous brother Loki.

"Thor 2" fell a bit short of industry forecasts that it would kick off with up to $92 million at North American (U.S. and Canadian) theaters. But the sequel opened stronger than the original movie, which debuted with $65.7 million in May 2011.

Thor also appeared in 2012 smash hit movie "The Avengers," which helped stoke interest in the character. According to a poll by the Fandango movie website, 72 percent of ticket buyers said fond memories of Thor in "Avengers" influenced their choice to see "Thor: The Dark World." The "Thor" sequel cost $170 million, Disney said.

"It's a great start," said Dave Hollis, executive vice president of distribution for Walt Disney Studios, adding that Disney would have considered "anything north of $80 million to be a good result."

Hollis also noted that the film was playing especially well with family audiences.

"Marvel has transitioned," he said. "This is an everybody picture." Business ticked up as the weekend went on, and he said Disney was anticipating an especially strong performance on Sunday and Monday, given the Veterans Day U.S. holiday on Monday, when many schools and businesses will be closed.

Second-place film "Bad Grandpa" stars comedian Johnny Knoxville in disguise as an 86-year-old man who travels cross-country with his 8-year-old grandson, pulling pranks on unsuspecting people they encounter on the way.