While at St. Paul's Rice Park to go ice skating with friends on Thursday night, Joy Son of Minneapolis said she started snapping pictures on her phone of the park's holiday lights.

It wasn't until someone whispered to her that a proposal was happening down the path that she said she bothered to look down.

Son quickly tried to zoom in to capture the moment, she said, but thought she had missed it -- until she scrolled through her camera roll and found the photo that she later posted on Instagram. It perfectly captured the moment of the proposal, a man on bended knee and a woman reacting with surprise. The image was taken at 9:57 p.m.

I was so busy trying to take a photo of the tree lights, I didn’t see that I actually captured a proposal! I’d love the chance to share this with the couple and would appreciate any help! This was at Rice Park in St. Paul on 12/18/14 around 10:00pm. A photo posted by joy son (@joyson) on Dec 12, 2014 at 10:11pm PST

The photo went viral on Instagram and Facebook on Friday, with thousands of likes, shares and comments as people tried to track down the couple.

It wasn't as easy as it seemed at first.

By happenstance, another similarly dressed couple became engaged in Rice Park, as captured by Studio48 photography. After a thorough comparison of each photo set, however, it was clear the two couples were different. Romance was clearly in the air.

By late in the day, the mystery was solved, with 22-year-old Stephanie Yarian, a student at the University of Northwestern in St. Paul, coming forward to tell Fox9 that the photo captured the proposal from her fiance, Luke Peterson, a recent graduate of Minnesota State University, Mankato.

Yarian told Fox9 that she'd been seeing the photo "all over" social media after friends alerted her to the photo and story at StarTribune.com, adding that she and Peterson are thrilled that their special moment was captured in such a special way.