Boisson is by far the lowest-ranked woman to beat someone ranked in the top five at the French Open in 40 years.

Loïs Boisson had never even played at the French Open before, let alone in the biggest arena at Roland-Garros, and now the unseeded 21-year-old Frenchwoman is through to the quarterfinals.

American Jessica Pegula, the world No. 3-ranked woman, lost to world No. 361 Lois Boisson in a shock French Open upset Monday. Boisson electrified the local crowd as she advanced to the quarterfinals, the only man or woman to reach the round this year.