Friday's premiere drew an estimated audience of 17.2 million, which would make it the most-watched basic cable program ever, according to Nielsen Media Research. It more than doubled the viewership of the first movie, "High School Musical," which drew 7.7 million in 2006.
The basic cable record had been held by a "Monday Night Football" game on ESPN in 2006, which was watched by 16 million.
"High School Musical" has become a cultural phenomenon with hit records, concerts and newly minted young stars including Ashley Tisdale and Zac Efron. The sequel followed the summer adventures of students Sharpay and Troy and their fellow Wildcats of East High.