If you wait long enough, it's not a sequel, it's the beginning of a whole new franchise. So it is with 'TRON: Legacy,' which proved so huge in its first three days that it rendered the original movie 28 years ago a mere footnote in the reboot's success.

'TRON: Legacy' dominated the box office with an estimated $43.6 million, about $17 million more than the 1982 'TRON' earned during its entire run. You'd think a sequel to a movie made nearly 30 years ago and beloved only by a cult of fanboys would face an uphill climb at the box office, but Disney deserves a lot of credit for expertly marketing the sequel, making sure it had state-of-the-art special effects, getting Jeff Bridges to return as the star (and to play opposite a CGI version of his younger self), and getting it into as many 3-D and IMAX theaters as possible.

In fact, IMAX screens made up more than 25 percent of the movie's midnight opening take of $3.6 million early Friday, a record ratio for IMAX. Those spectacle surcharges, plus enthusiastic word-of-mouth, should keep the new 'TRON' a top moneymaker throughout the holiday season. Not to mention ensuring that Disney doesn't wait another 28 years before making 'TRON: Legacy: Legacy.'

Even so, given the hype, many pundits expected 'TRON: Legacy' to open even bigger, with estimates as high as $54 million. Similarly, 'Yogi Bear' was expected to open between $18 and $23 million, but it debuted with an estimated $16.7 million. Still, that was enough for an easy second-place finish for the 3-D adaptation of the old cartoon favorite. Reviews were unkind, but young children obviously didn't mind (save for 'Tangled,' there was little else targeted at them), and lthe extra cash from glasses rentals didn't hurt.

Last week's No. 1, 'The Chronicles of Narnia: The Voyage of the Dawn Treader,' actually did a smidge better than expected. After its weak opening, it was expected to have a second-weekend dropoff in the range of the first 'Narnia' movie (51 percent) or the second (59 percent), but it slipped just 48 percent to an estimated $12.4 million and a third-place finish. Still, even though it's earned only $42.8 million domestically, it's earned twice that overseas, so the prospect of a fourth 'Narnia' film seems secure.

'The Fighter'Just a jab or two behind 'Dawn Treader' was 'The Fighter,' which expanded this week from four screens to 2,503 and earned an estimated $12.2 million. That was within the $11-to-$15 million range of expectations, which took into account the movie's impressive opening last week ($75,000 per screen, slightly below initial estimates) and its massive awards-season buzz, including Golden Globe nominations for Best Drama, Best Director and for its four principal stars.

Rounding out the top 5 was 'The Tourist,' which lost 47 percent of its business due to weak word-of-mouth and took in another estimated $8.70 million. (That's just a hair more than the estimated $8.68 million for 'Tangled,' so when final numbers are released Monday, the two may switch places.) 'The Tourist's' two-weekend total is $30.8 million.

Two other movies entered the wide-release marketplace this weekend. One was 'Black Swan,' which vaulted from 90 to 959 screens and earned an estimated $8.3 million, good for seventh place. As with 'The Fighter,' positive reviews and strong Oscar buzz have made the Natalie Portman drama a big want-to-see, as reflected in 'Black Swan's' $8,655 per-screen average, second only to 'TRON: Legacy' among this week's wide releases.

The other, 'How Do You Know,' was a disappointment, opening at No. 8 with an estimated $7.6 million. Given a strong cast (Reese Witherspoon, Owen Wilson, Paul Rudd, and Jack Nicholson) and a lack of romantic-comedy competition, the movie had been expected to open between $10 and $13 million, but it sank beneath the weight of lackluster reviews.

The full top 10:
1. 'TRON: Legacy,' $43.6 million (3,451 screens), new release
2. 'Yogi Bear,' $16.7 million (3,515), new release
3. 'The Chronicles of Narnia: The Voyage of the Dawn Treader,' $12.4 million (3,555), $42.8 million total
4. 'The Fighter,' $12.2 million (2,503), $12.6 million
5. 'The Tourist,' $8.70 million (2,756), $30.8 million
6. 'Tangled,' $8.68 million (3,201), $127.8 million total
7. 'Black Swan,' $8.3 million (959), $15.7 million
8. 'How Do You Know,' $7.6 million (2,483), new release
9. 'Harry Potter and the Deathly Hallows: Part I,' $4.8 million (2,860), $265.5 million
10. 'Unstoppable,' $1.8 million (1,874), $77.3 million

•Follow Gary Susman on Twitter @garysusman.