The 22-year-old had just started her short dance routine at the Winter Olympics when her dress came undone, leaving her breast exposed.
Papadakis "felt it right away and prayed", continuing her routine with partner Guillaume Cizeron to deliver a performance that leaves them in second heading into Tuesday's free dance.
"It was pretty distracting," she said.
"My worst nightmare at the Olympics. I told myself 'you have to keep going'.
"That's what we did, and we have to be proud of ourselves, delivering a great performance with that happening."
The Olympic debutants' samba-rhumba-samba to two Ed Sheeran hits earned them 81.93 points, only behind Canada's Tessa Virtue and Scott Moir who posted a world record score of 83.67.
The mishap took place when Papadakis leaned backwards early on and Cizeron inadvertently managed to unclip the back of her green costume.
"It's just frustrating to miss a few points because of a costume issue. It is not what we get ready for when we train," said Cizeron afterwards.
It is not the first wardrobe malfunction to occur at the Games in Pyeongchang, with a clasp on South Korean figure skater Yura Min's dress slipping just seconds into her pairs figure skating routine.
Both incidents still pale compared to Russian skater Ekaterina Rubleva at the 2009 European Championships, whose pink dress slipped down almost to her stomach.