The 2012 Olympic Games have come to an end on a bittersweet note for Marlen Esparza…

The 23-year-old first generation Mexican American boxer—the first American woman to earn an Olympic berth in boxing—lost to reigning world champion Ren Cancan of China in the flyweight semifinal of the inaugural women’s boxing competition at the London Games.

Esparza, guaranteed at least a bronze medal heading into the bout, trailed throughout the four rounds by margins of 3-2, 7-4, and 8-6 as Cancan won a cautiously fought encounter in a rematch of their boutat this year’s world championships, which the Chinese star won.

The first round was devoid of substantial action as both boxers sized each other up and measured their striking distance. As the clash progressed Esparza, who was constantly bouncing on the balls of her feet, tentatively waited on her foe to make a mistake and leave an opening to attack.

When neither switching from the orthodox to southpaw stance nor counterpunching tactics worked for Esparza, she finally pressed forward in the fourth and final frame, scoring with a late flurry that she hoped would tip the close fight in her favor.

Unfortunately Esparaza, who has garnered national attention for her advertisements for CoverGirl and McDonald’s, would fall just short but will still make the medal stand.

“I thought I was going to win … I thought I was going to win,” Esparza said through tears Wednesday after the 10-8 loss to Ren. “I thought I was going to win, so this is very difficult.”

Esparza and fellow semifinalist Mary Kom of India have automatically been awarded bronze, as there is no third-place bout under Olympic rules.

So despite the heartbreaking loss, Esparza has cemented her place in American sports history as the first to clinch an Olympic medal. And, she’s still an inspiration to millions of girls around the country.

Esperza, known for her speed and smarts in the ring, graduated in the top 2% of her class and was student body president in high school.