In China, however, the 21-year-old was drawing wide attention for another reason, as news spread that the Canadian girl who beat China's top woman swimmer, Zhang Yufei, by 0.05 seconds was actually born in China and adopted as a baby by a Canadian couple.
The subject of MacNeil soon lit up Chinese social media. A hashtag about her victory became the top trending topic on Chinese microblogging site Weibo on Monday morning, and has since drawn nearly 400 million views. Much of the attention has focused on her Chinese heritage -- and reflections over the wider social and political circumstances that led to her adoption by a foreign family.