The Toxic singer, who is mentoring the teens, could even win the competition, said the TV mogul who sits beside her on the panel alongside Antonio 'LA' Reid and Demi Lovato, reported Access Hollywood.
"They're super, super talented this year. Everybody, in a way, wanted that category. Britney, she got them and she was absolutely thrilled. From what I hear, she's doing a good job," Simon said.
"She's been a lot better than everybody thought. She's very engaged. She has been a very, very good judge. She thinks she can win the competition."
Khloe, adding to her reality TV credentials, was paired with Mario Lopez to emcee X Factor as the singing contest shifted from taped to live broadcasts.
Mario, host of Extra, performed like the pro he is.
Khloe, by contrast, shouted her lines despite the mic clutched in her hand and made awkward small talk with contestants and judge Simon.
Simon defended her by saying: "On live TV, things do go wrong. I kind of like to see the unpredictable and I quite like seeing people under pressure and see how they deal with it. You don't want robots, you want human beings."
Of the 16 acts featured on the live X Factor, four will be cut by judges Britney, Simon, LA Reid and Demi. Viewers will decide contestants' fates in following weeks.