CBS’ ‘Supergirl’ is this fall’s most-watched series premiere

“Supergirl” can really lift those ratings.

Monday’s premiere on CBS of TV’s latest superhero franchise drew 12.9 million total viewers, according to Nielsen, making it this fall’s most-watched series premiere.

Admittedly, it’s been a tough season so far for broadcasters, but the results have to give CBS executives reason for hope. Starring 20-something Melissa Benoist as a young woman who balances ordinary office life with a secret existence as a superhero, “Supergirl” is an effort to bring not just super powers but youth to a network that has skewed old for decades.

Full coverage: Fall TV guide 2015

CBS projects that the show’s audience will climb to nearly 19 million over the next week, once delayed viewing is tabulated.

Among viewers aged 18 to 49 — the group advertisers care about most — “Supergirl” scored a 3.2 rating and was virtually neck-and-neck with NBC’s youth-loving singing contest “The Voice,” which it aired opposite against.

Yes, but does “Supergirl” have the stamina to stay strong? Those questions and others will be answered over the following weeks.

What did you think of “Supergirl”?

Twitter: @scottcollinsLAT