Osmond had just completed an energetic samba with her partner, professional dancer Jonathan Roberts, when she crumpled to the floor.
When the show returned from a commercial break, host Tom Bergeron said: "Marie is fine. ... She passed out." He added that when she came to and saw everyone standing over her, the first words out of her mouth were, "'Oh, crap.'"
"Once in a while it happens to me when I get winded," Osmond said later. "I just stopped breathing."