Gleefully referencing her appearance on the infamous “Sarah Palin episode” of Saturday Night Live, Adele giggled to Shanghai 1930’s packed room, “I guess it didn’t work out so well for her, but it certainly worked out for me!” Indeed it did. An established hit-maker in her native UK, Adele had yet to break into the American music scene by late 2008. That is, until she scored the musical spot on SNL’s October 18 episode, was seen by an estimated 14 million viewers, and topped the iTunes charts the very next day.

If the turnout on November 20 was any indication, Adele needn’t worry about winning fans this side of the pond anymore. Presented by San Francisco radio station, Alice (97.3), the intimate performance was stadium-worthy. Sizing up the happy hour crowd, Adele lamented, “I wish I were legal!” thus providing the only reminder of the evening that the singer is all of twenty years old (her debut album, 19, is titled for her age at the date of its release). While fans may be aware of her astoundingly mature sound on the single, “Chasing Pavements,” Adele’s recorded tracks hardly do her live vocals justice. Effortlessly hitting every note with pitch-perfect precision, Adele’s mesmerizing performance seemed to take groupies and casual observers alike by total surprise.

Accompanied by guitar player, Ben Thomas, and keyboardist Miles Robertson, Adele allowed the music to speak for itself. Perched on a stool, the singer belted out song after song, eagerly performing two encores. Unpretentious, yet unbelievably polished, Adele exuded the cool confidence of an old pro, while retaining the infectious enthusiasm of a young girl on the brink of stardom.

The singer’s January return to San Francisco has already been moved from The Filmore to the Warfield to accommodate her massive fanbase. So even though she may have gotten a little boost from the allure of a certain Alaskan VP wannabe, it’s pretty clear that Adele would have won over the majority all on her own.