Disney's long-anticipated TV film High School Musical 2 has reportedly become the most-watched programme of all time on basic cable channels in the US.
The made-for-TV movie stars Zac Efron and Vanessa Hudgens
About 17.2 million people tuned in to see the song-and-dance spectacular make its debut on the Disney Channel on Friday, the Hollywood Reporter said.
The audience for the premiere was larger than that for the four main TV networks combined, it was reported.
High School Musical 2 gets its first UK screening on Disney on 21 September.
The original made-for-TV movie was an unexpected success for Disney in 2006, with profits estimated to be in excess of $100m (£50m) from a budget of just $4m (£2m).
Described as a modern-day Grease, it was seen by more than 200 million viewers in 100 countries and its soundtrack became the best-selling album of 2006 in the US.
School productions of the show sprang up all over the world as young viewers took the story - of a brainy student and sports captain competing for roles in a school musical - to heart.
The phenomenon largely caught Disney by surprise, and it had to scramble to put a marketing and merchandise plan into action.
For the sequel, nothing has been left to chance.
Cherie Blair attended the UK premiere of the first movie in 2005
"What's different for the second one is that demand is soaring," said Rich Ross, president of Disney Channel Worldwide.
"Every division at Disney has figured out how it makes sense for their products to roll out."
The company is expected to have 100 High School Musical products, ranging from shoes to backpacks, in stores in time for Christmas, while an ice-skating spin-off launches next month.
A movie is also underway, which will get a cinema release in 2008.
The TV sequel reunites the cast of the original, including stars Zac Efron and Vanessa Hudgens.
Set in the summer holidays, it sees the cast reunited at an upmarket country club where they have all landed summer jobs.
Reviews have largely been positive. USA Today called it "a first-rate family film", while Time magazine said it promised "an unembarrassed good time".
Ashley Tisdale plays the scheming Sharpay Evans in the musical
The New York Times was less kind, calling the movie mediocre and the actors badly fake-tanned, although it conceded the production had "haphazard charm."
The previous record for basic cable viewing was held by sports network ESPN, which attracted an average of 16 million viewers to an American football game in 2006.
The 17.2 million figure for High School Musical 2 would have been higher if analysts had taken into account the large viewing parties held by fans across the country, the trade paper said.
"Breaking the viewership record is terrific, but records come and go," said Gary Marsh, entertainment president at Disney Channel Worldwide.
"What's really important is the impact the High School Musical movies have had on kids all over America and all over the world.
"These movies have empowered kids to express themselves in whole new ways and have changed their lives forever."