The 28-year-old Sierra covered 157.7 kilometers, starting in the town of Antwerp, and finishing here in 3:52.28 hours, one second behind Italian champion Elisa Balsamo.
Accompanying the Italian cyclist on the podium were Mariane Voz (3:52.27), from the Netherlands, and Katarzyna Niewiadoma (3:52.28), from Poland.
In fourth place was Blanka Vas (Hungary), followed by Sierra, who was ahead of Alison Jackson (Canada), all three with the same time.
This was Sierra’s best performance in her career in such championships, in which she finished in the 12th place during the 2019 edition in Yorkshire, the United Kingdom.
Meanwhile, Balsamo beat Dutch star Anna van der Breggen and regained the crown for her country that previously celebrated Giorgia Bronzini’s victory in 2011.