The fourth seat at the "American Idol" auditions judge's table has welcomed some of the hottest stars this summer. Simon Cowell tells "Extra" he especially enjoyed working with "feisty" pop rocker Katy Perry.

Cowell reluctantly revealed the "Waking Up in Vegas" songstress wasn't afraid to stand up to him during the judging process. "She's a feisty little thing," he dished. Adding, "She's quirky. Definitely got her own opinion."

Simon explained, "Solo artists are not used to people disagreeing with them. They are feisty and I like that."

Cowell is the headstrong and honest judge on the panel, but he says he still won Perry over. "I don't think she knew quite how right I was until she sat next to me," he confidently declared.