Keith Urban wasn't the only one to cry during Kelly Clarkson's moving performance of "Piece by Piece" last week on American Idol. Clarkson sat down with Ellen DeGeneres this week to talk about the moving moment, revealing that she too was holding back tears during the performance — to her dismay.

"I came off almost in tears for a different reason because I was so embarrassed," Clarkson tells DeGeneres. "I was like, ‘Oh, God. This is my final thing on Idol and I could not hold it together.’ I was almost losing it almost the entire song. I was proud of myself for making it as far as I did."

It was an emotional day for Clarkson, as her 20-month old daughter River Rose and her husband were on the set with her — the same set where the now superstar got her start when she was just a teenager.

“I didn’t realize it was going to be that bad. And we were rehearsing that day and I just couldn’t get through it. My 1-year-old is running around the same hallway as I was at 19,” she recalls. “[Brandon is] a great husband and a great father. And he was there, my little girl was there, my little boy was, like, turning circles in my stomach. It was nostalgic. It was the last time I was going to be on Idol and it’s ending. I was screwed from the get-go.”

"Piece by Piece" came from real inspiration, after Clarkson and her sister talked about how lucky they are that they've both found such supportive and loving husbands, in spite of a rough relationship with their dad.

"It's sad but hopeful," Clarkson says of the powerful song. "A lot of us didn't have a bar to set as far as finding love and relationships or friendships in any form. My sister and I had a conversation and afterwards I ended up writing a song about how lucky we are because we both found incredible fathers and incredible lovers and men and partners. I feel really lucky because a lot of girls with daddy issues don't end up that way. We end up going the same."

Poking fun at herself at the dramatic performance, the star concludes, “Emotionally, I was on a slip-and-slide from hell.”

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