"Dancing With the Stars" had its first onstage disaster Monday night.
Just seconds into their rumba routine to "Somewhere Over the Rainbow" on Monday, Chmerkovskiy wiped out, taking the 60-year-old actress down with him.
A limping, apologetic Chmerkovskiy later told the judges that his thigh "just gave out."
After a few moments the pair recovered and went on to earn the praise of the judges and a score of 21 - one point higher than their score for last week's quickstep.
Judge Carrie Ann Inaba says, "Sometimes tragedy leads to amazingly beautiful moments."
After the show, Chmerkovskiy tweeted his apologies to Alley and their supporters.
"To all the fans...I'm sorry! It will never happen again and I will never 'fall'! To @kirstiealley You were..FLAWLESS! In more ways than one!"