Helen Maroulis, left, of the United States, celebrates her win over Marcia Andrades, of Venezuela, after pinning her in the second period during an exhibition match at Times Square, Wednesday, May 7, 2014, in New York. Wrestlers competing in the exhibition included past and potential future Olympic athletes from the USA, Russia, Bulgaria, Venezuela and Canada. (AP Photo/Julie Jacobson)

The United States has never had a female wrestler win a gold medal at the Olympics.

The Americans could have a pair of champions by the end of Thursday's freestyle tournament. 

Three-time world champion Adeline Gray is a heavy favorite in the 75-kilogram weight class, while Helen Maroulis is a serious medal contender at 53 kilograms.

Gray's top challenger will likely be Aline Da Silva Ferreira, a silver medalist from the world championship in 2014 who'll no doubt be backed by a boisterous home crowd.

Maroulis, who won a world title at 55 kilograms in 2015, will find herself up against the toughest opponent of her career if she and Japan's Saori Yoshida reach the finals.

Yoshida is a 16-time world champion _ including three Olympic titles _ and she hasn't lost in a major tournament in years. But Yoshida's margins of victory have shrunk in recent tournaments, and Maroulis hasn't lost a match in two years.

Thursday could turn out to be a turning point for the U.S. women's program, which is hoping to halt Japan dominance of a sport which now has six Olympic weight classes.

But the Americans will rue their missed opportunities it they Rio without a gold medal.  

"We have paid our dues, and it’s our time," U.S. coach Terry Steiner said.