Yes, That's Justin Guarini In That Diet Dr Pepper Commercial

Justin Guarini is back on the small screen, but he looks very different from his "American Idol" days.

The former "Idol" runner-up makes sweet music as Diet Dr Pepper's "Lil Sweet," looking unrecognizable in a long purple wig in the latest commercial titled "Birthday." Lil Sweet comes to the rescue in the latest 30-second ad spot by bringing the zero-calorie beverage to a cupcake-filled birthday party.

The first Lil Sweet ad debuted in February.

Guarini made a name for himself in Season 1 of "American Idol." After losing to Kelly Clarkson, he went on to co-star with her in the box-office bomb "From Justin to Kelly" and try his hand as a recording artist. He has been performing theater for the past 10 years, including a handful of Broadway shows. In 2013, he wrote a blog post about the struggles of his post-"Idol" life.



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