No. 2-ranked Iga Swiatek lost to a player younger than 18 for the first time on tour when she was stunned by Mirra Andreeva in the Dubai Championships quarter-finals on Thursday.

Andreeva, 17 won 6-3, 6-3 to become the youngest semi-finalist in Dubai’s 24-year history. It’s her fifth win over a top-10 player and second over a No. 2 — she beat Aryna Sabalenka in the French Open quarters last year.