Clarkson, 37, didn't miss a beat.
When she realized cameras captured her embarrassing moment, the Texas native simply took a bow and kept it moving.
She retweeted a video of herself tripping, writing, "best part of my day is always revealing to people that might not know how utterly not cool I am. That damn crack was hidden by the carpet man! #Indy500."
Clarkson, who performed "The Star-Spangled Banner" at racing's biggest day, also slammed a Twitter user who dissed Chevel Shepherd, the 16-year-old winner of "The Voice" Season 15.
"@kellyclarkson Indy 500 - Absolute WORST version of God Bless America I’ve ever heard!!! Sing it the way it was written, without all the slow whining, the 'stylizing,' the chirps and warbles. Want to know how to sing it right? Listen to Kate Smith’s version," the hater wrote.
Clarkson clapped back, "I didn’t actually sing that song today but the 16 yr old girl that did, nailed it. Also, think about the fact that U signed in online & took the time 2 drag a 16 yr old girl. Really think about it because Ur showing the worst side of U & I have faith that you’re cooler than this."