Coco Gauff of the U.S. celebrates as she won the semifinal match of the French Tennis Open against France's Lois Boisson at the Roland-Garros stadium in Paris.

Winner Coco Gauff of the U.S., left, and France's Lois Boisson shake hands after their semifinal match of the French Tennis Open at the Roland-Garros stadium in Paris.

Winner Coco Gauff of the U.S., right, applauds as France's Lois Boisson leaves the court after their semifinal match of the French Tennis Open at the Roland-Garros stadium in Paris.

Coco Gauff of the U.S. plays a shot against France's Lois Boisson during their semifinal match of the French Tennis Open at the Roland-Garros stadium in Paris.

Coco Gauff of the U.S. plays a shot against France's Lois Boisson during their semifinal match of the French Tennis Open at the Roland-Garros stadium in Paris.

France's Lois Boisson reacts as she plays against Coco Gauff of the U.S. during their semifinal match of the French Tennis Open at the Roland-Garros stadium in Paris.

France's Lois Boisson plays a shot against Coco Gauff of the U.S. during their semifinal match of the French Tennis Open at the Roland-Garros stadium in Paris.

Coco Gauff of the U.S. is reflected in a glass as she plays a shot against France's Lois Boisson during their semifinal match of the French Tennis Open at the Roland-Garros stadium in Paris.

France's Lois Boisson serves against against Coco Gauff of the U.S. during their semifinal match of the French Tennis Open at the Roland-Garros stadium in Paris.

Coco Gauff of the U.S., bottom, plays a shot against France's Lois Boisson during their semifinal match of the French Tennis Open at the Roland-Garros stadium in Paris.