Blond ambition was in full effect on tonight's episode of  'American Idol,' as Season 4 winner Carrie Underwood returned to the stage that launched her career to sing her biggest hit, 'Before He Cheats,' with finalist and 'Idol' wannabe Lauren Alaina, who pretty much reveres Underwood.

Alaina is essentially an Underwood mini-me and we mean that as a compliment: She's adorable, she's blond and she sings pop-country crossover in the same vein as Underwood. She also has the most adorable Southern accent.

So when the ladies teamed up to blast through 'Before He Cheats,' it was also symbolic. Alaina is thisclose to being a literal Underwood successor as an 'Idol' winner. If that does indeed happen, Alaina should thank Underwood, since she chose Pam Tillis' 'Maybe It Was Memphis' for Alaina's performance last night and that was the one song that judges believed put the teen over the top and gave her a decided edge over Scotty McCreery.

Watch Lauren Alaina and Carrie Underwood Perform 'Before He Cheats' on 'American Idol'