Oops! How Paula Abdul Accidentally Injured Julianne Hough

Hough was hit directly in the neck by Paula Abdul's flying hat, which was thrown into the crowd during her show-stopping performance of a medley of her hits.

Julianne seemed surprised by the impact, but still managed to smile for the cameras.

After the show, Hough posted a pic of herself wearing a white neck brace while flashing two thumbs-up. She captioned the Twitter pic, “The result of the honor of being hit in the neck by @PaulaAbdul's flying hat! Love you, babe!!!”

Paula responded to Julianne's tweet, writing, “OMG IM PEEING MY PANTS!!!!! You know it was with love.”

During Paula's set, she showed off her dancing skills while performing her breakthrough smash “(It's Just) The Way That You Love Me,” as well as chart-toppers "Straight Up," “Opposites Attract,” “Cold Hearted” and “Forever Your Girl.”

Before the show, “Extra's” Renee Bargh chatted with Paula, who revealed that she hadn't performed on an award show “in 29 years.”

She also admitted that she was “fangirling” over Taylor Swift. She said, “I saw her at an 'American Idol' taping, but I never really got to talk to her and today I got to talk to her… I met the cats, I'm really, really excited, and I'm allergic to cats, but I had no reaction.”

Taylor also posted a pic of herself with Paula, writing on Instagram, “I'm trying to give them a normal upbringing but when the little ones and I ran into the flawless @paulaabdul on the way to red carpet we STRAIGHT UP had to get a pic.”

The 56-year-old appeared to be in good spirits just weeks after the death of her dad, who was battling Alzheimer's disease.