(JULY 21)  TORONTO, CANADA - 2012 Olympic champion Claressa Shields (Flint, Mich.) and Olympic bronze medalist Marlen Esparza (Houston, Texas) both made triumphant Pan American Games debuts on Monday afternoon at the Oshawa Sports Centre in Toronto, Canada. The Olympic duo clinched medals in their first Pan American Games with wins in Monday afternoon's quarterfinal competition. Bantamweight Francisco Martinez (Dallas, Texas) became the fourth U.S. boxer to advance to the semifinals with a TKO win in Monday's evening action. Middleweight Anthony Campbell (Covington, Tenn.) lost his quarterfinal bout in the final U.S. bout of the day. 

Esparza competed in the first women's bout of the 2015 Pan American Games in a flyweight contest with

Nicaragua’s Claudia Parrales Guevara. The reigning world champion showcased a dazzling display of boxing prowess in her Pan Am debut, landing a wide array of punches and evading Guevara's shots. She grew her lead with every round and took the victory by wide, unanimous decision to advance to the semifinals. Esparza will face Puerto Rico's Monica Gonzalez Rivera for a berth in the gold medal bout on Tuesday night. 

"I think it was a good fight and I got to get used to backstage and the canvas," Esparza said of her Pan Am debut. "She keeps her hands really tight so I was really just trying to go to the body and when I saw her coming in, that's when I'd go up top. I was really trying to do more movement so I don't just rush in. I'm working on that and that's where the bodywork comes in." 

Shields faced a familiar foe in her middleweight quarterfinal bout on Monday afternoon, taking on Brazil's Flavia Figueiredo. The Olympic and World Champion looked to set the tone early and take control of the bout. She landed several strong and fast shots early in the bout as the two traded intense combinations.  Shields continued to pepper Figueiredo from the ropes while avoiding the Brazilian's incoming punches. The two battled in a fun and active match-up for four rounds before Shields was named the winner by unanimous decision. She moves on a semifinal contest with Argentina's Lucia Perez on Tuesday night. 

"Flavia is a really good fighter. That's my third time fighting her. She always brings it every time we fight, I think she's one of the top five boxers in the game right now," Shields said. "I had great instruction from my coaches and I tried to listen. I just stayed composed when she was rushing me and I didn't get overwhelmed. I did more infighting than I wanted to but I did what I had to do. Today was a good fight, it was a tough one for me but the first match is always the hardest for me." 

Martinez continued the U.S. winning streak in his quarterfinal match-up with Farronan Cruzado Jorvi of Peru in the first American bout of Monday's late session action. He grabbed the attention of the crowd and his opponent with a strong left hook that sent Jorvi to the canvas. Jorvi returned to his feet but his struggles continued after a bad cut opened over his left eye. Martinez stayed focused on the task at hand until the doctor stopped the bout due to the cut at the 1:47 mark of the second round. Martinez advances to a semifinal contest with the Dominican Republic's Hector Garcia Mora on Wednesday evening. 

"I felt comfortable and loose and really excited. My game plan was to start with the jab first and use my jab to keep my distance. Once I was in my range, I wanted to land that straight right to the body, and come back with the hook," Martinez said. "I was going in there with my jab and I put my hands up once I get in close range. I noticed he was ducking his a lot so when he was coming back up, I timed him with that hook that I was looking for." 

Campbell got off to a strong start in his middleweight quarterfinal bout with Mexico's Misael Rodriguez Olivas, winning the first three rounds on all three judges' scorecards.  Yet he couldn't continue his momentum over the next two rounds and Olivas took a 3-0 decision in the match. 

"I was hitting him with hard shots and he was just walking right through. It was a good fight though," Campbell said. "I feel like I lost not because I wasn't in shape but because he was the better man tonight." 

Five American boxers will compete in Tuesday's competition at the Oshawa Sports Centre. Two tough bouts will kick off the day for Team USA. Flyweight Antonio Vargas (Kissimmee, Fla.) will face 2016 Olympian Jeyvier Cintron Ocasio of Puerto Rico while light welterweight Luis Feliciano (Milwaukee, Wis.) takes on Cuba's Yasnier Toledo. In the evening session, lightweight Carlos Balderas (Santa Maria, Calif.) will compete for the first time at the Pan American Games in a match with Mexico's Lindolfo Delgado. The United States' two female athletes will both compete in semifinal competition late in Tuesday's competition. 2012 Olympic bronze medalist Marlen Esparza (Houston, Texas) will battle Puerto Rico's Monica Gonzalez Rivera and Olympic champion Claressa Shields (Flint, Mich.) will challenge Argentina's Lucia Perez. 

Coaches Ed Weichers (Colorado Springs, Colo.), Israel Acosta (Milwaukee, Wis.) and Joe Guzman (Fountain, Colo.) are leading the United States boxing team at the 2015 Pan American Games.

U.S. Results

112 lbs/female: Marlen Esparza, Houston, Texas/USA dec. Claudia Parrales Guevara, NIC, 3-0

123 lbs/male: Francisco Martinez, Dallas, Texas/USA won on TKOI over Farronan Cruzado Jorvi, PER, TKOI-2

165 lbs/female: Claressa Shields, Flint, Mich./USA dec. Flavia Figueiredo, BRA, 3-0

165 lbs/male: Misael Rodriguez Olivas, MEX, dec. Anthony Campbell, Covington, Tenn./USA, 3-0