The boxing tournament of the 2015 Pan American Games starts its first competition day tomorrow in Toronto, Canada.

A total of 120 men and women will compete in Toronto across 13 weight classes, as boxers who qualified through both the World Series of Boxing (WSB) and the qualifying event will compete to determine who is the best in the Americas region.

With not long to go until the in-ring action begins, we have previewed every weight category in the competition to determine who are the favourites, and who may cause some surprise results.

Women’s Flyweight class (51 kg)

Current AIBA Women’s World Champion Marlen Esparza also won the Pan American Games Qualifier last month where the American defeated her rival Mandy Bujold.

Canada’s Bujold earned a gold medal in the last edition of the Pan American Games however, and will be inspired to defend her title on home soil in front of her supportive fans.

Colombia’s Central American & Caribbean Games winner Ingrid Valencia engaged in a close bout against Esparza one month ago, and she will take enormous confidence from that match into Toronto.

Venezuela’s 2013 AMBC American Women’s Continental Championships gold medalist Tayonis Cedeno is another boxer to watch out for in this weight category.

Women’s Lightweight class (60 kg)

Canada’s Caroline Veyre won gold medal at the Pan American Games Qualifier which makes her the favourite to triumph once more in her home tournament.

Her main rivals include Puerto Rico’s Kiria Tapia, Mexico’s Victoria Torres and Dominican Republic’s Mirquin Jahaziel Sena.

El Salvador’s promising hope Karla Herrera who trains in Los Angeles, and Dominica’s lone representative Valerian Spicer who trains in the United Kingdom will both be hoping their international experience will enable them to perform well in Toronto.

This weight class is one of the most difficult to predict in terms of medal winners, especially as both US National Champion Mikaela Mayer and Brazil’s London 2012 Olympic Games bronze medallist Adrianna Araujo could not qualify for the Games.

Women’s Middleweight class (75 kg)

A big battle is expected to take place between USA’s defending AIBA Women’s World Champion and London 2012 Olympic Games gold medalist Claressa Shields against Canada’s former two-time AIBA Women’s World Champion Ariane Fortin-Brochu.

Elsewhere, Dominican Republic’s AMBC American Women’s Continental Champion Yenebier Guillen and Brazil’s South American Games winner Flavia Figueiredo are further strong boxers in the women’s Middleweight class.

Men’s Light Flyweight class (49 kg)

Mexico’s Joselito Velasquez is the defending champion in this weight category after he achieved gold four years ago, and the 22-year-old recently enjoyed a successful season in WSB.

The Mexican star defeated Cuba’s 2013 AIBA Junior World Champion Joahnys Oscar Argilagos Perez in Season V of that competition, and the Cuban athlete will be aiming for revenge in Toronto.

Other medal candidates include Colombia’s Yubergen Martinez, while Venezuela’s 19-year-old Yoel Finol reached the quarter-finals of the 2014 AIBA Youth World Boxing Championships, and secured his quota for the Games after a great WSB season.

Nicaragua’s Pan American Games Qualifier winner Kevin Adonis Arias won four tough bouts in Tijuana last month, and US National Champion Melik Elliston is a technical boxer who often performs to a high standard.

Men’s Flyweight class (52 kg)

Cuba’s Yosbany Veitia was the top ranked Flyweight in WSB last season, and has excelled at the international level over the past few years.

Although the Cuban is a strong favourite for gold, many fans are tipping Puerto Rico’s Jeyvier Cintron for success, while United States’ talented 19-year-old Antonio Vargas is another exciting prospect.

Dominican Republic’s Central American & Caribbean Games winner Leonel De Los Santos has recently moved up to Flyweight, while Costa Rica’s David Alejandro Jimenez and Brazilian veteran Juliao Henriques Neto are also among the medal contenders.

Men’s Bantamweight class (56 kg)

Hector Luis Garcia has only lost a single bout this year, and the Dominican Republic fighter made a huge mark on Season V of WSB when he took the undefeated record of Magomed Gurbanov.

20-year-old Andy Cruz Gomez has the task of replacing London 2012 Olympic Champion Robeisy Ramirez in the Cuban team, and Canada’s former AMBC American Continental Championships silver medallist Tanjit S. Lally will be looking to use his ample experience in Toronto.

US National Trials winner Francisco Martinez, Ecuador’s Strandja Memorial Tournament silver medallist Segundo Padilla and Guatemala’s Central American & Caribbean Games silver medallist Juan Reyes all have the ability to perform well in Canada.

Men’s Lightweight class (60 kg)

Cuba’s two-time AIBA World Champion and London 2012 Olympic Games bronze medallist Lazaro Alvarez has been in exceptional form this year, but faces stiff competition in Toronto from Venezuela’s Luis Cabrera.

Dominican Republic’s 19-year-old Elvis Severino Rodriguez will look to continue his progress, while Colombia’s Pan American Games Qualifier silver medallist Faider Luis Hernandez, Mexico’s WSB hope Lindolfo Delgado and US National Trials winner Carlos Balderas all have the capacity to cause upsets in the Games.

Men’s Light Welterweight class (64 kg)

Cuba’s Yasnier Toledo is one of the most highly skilled boxers in the world, and he heads an impressive Light Welterweight field.

Potential rivals include Brazil’s decorated Joedison Teixeira plus Mexico’s Raul Curiel who earned a Rio 2016 Olympic Games quota through his recent WSB exploits.

Venezuela’s Luis Arcon reached the quarter-finals of the 2013 AIBA World Boxing Championships, and Canada’s Cheo Aponte Tournament bronze medallist Movladdin Biyarslanov is also being tipped to impress.

Men’s Welterweight class (69 kg)

An outstanding field of Welterweight boxers will compete in Toronto, headlined by Cuba’s London 2012 Olympic Champion Roniel Iglesias and Venezuela’s AIBA World Boxing Championships bronze medallist Gabriel Maestre.

Current AMBC American Continental Champion Roberto Custodio Queiroz is another potential rival for Iglesias, with Dominican Republic’s Nanjing 2014 Youth Olympic Games silver medallist Juan Ramon Solano keen to make his mark on a major senior competition.

Bahamas’ top boxer Carl Heild has claimed medals in multiple Commonwealth Games, while Argentina’s Alberto Ignacio Palmetta, Mexico’s Marvin Cabrera and US National trials winner Brian Ceballo have all achieved significant success in their careers.

Men’s Middleweight class (75 kg)

Cuba’s Arlen Lopez is one of the fastest rising stars in the world of boxing, and is keen to follow his gold medal at the Central American & Caribbean Games with another triumph in Toronto.

Potential rivals include Colombia’s Jorge Luis Vivas, plus the dynamic Raul Sanchez.

There is plenty of strength in depth at Middleweight, especially with excellent competitors such as USA’s Anthony Campbell and Canada’s newly crowned National Champion Clovis Drolet all hoping for gold medal supremacy.

Mexico’s tough Misael Rodriguez and Costa Rica’s Pan American Games Qualifier silver medallist Jason Ramirez are additional medal hopefuls.

Men’s Light Heavyweight class (81 kg)

Cuba’s two-time AIBA World Champion Julio Cesar De La Cruz lost to Ecuador’s rising star Carlos Mina in Season V of WSB, and their possible Pan American Games rematch could be a spectacular highlight of the boxing tournament.

Other Light Heavyweights to watch out for include Colombia’s exciting Juan Carlos Carrillo, plus Venezuela’s Albert Ramon Ramirez who earned a 5-1 record last season in WSB.

Brazil’s South American Games winner Michel Borges, United States’ Steve Nelson, and Mexico’s Rogelio Romero also represent dangerous opposition in Canada.

Men’s Heavyweight class (91 kg)

Cuba’s Erislandy Savon has been undefeated since October 2013, and most recently defeated world class Kazakh star Vasiliy Levitt in the WSB Season V Finals.

Heavyweight is a packed best weight division in the Pan American Games however, and the Cuban will have to defeat some superb opponents in order to add another gold to his collection.

Colombia’s defending AMBC American Continental Champion and Beijing 2008 Olympian Deivis Julio is vastly experienced, while Canada’s 35-year-old Samir El Mais won the Commonwealth Games last year in Glasgow.

Ecuador’s former AMBC American Continental Champion, Brazil’s Juan Nogueira and Chile’s South American Games silver medallist Miguel Angel Veliz both carry power which will threaten their rivals in Toronto.

Men’s Super Heavyweight class (+91 kg)

Cuba’s defending Heavyweight Pan American Games winner Leinier Pero moved up to the Super Heavyweight class (+91 kg) last year, and is aiming for a second successive gold medal in the Games.

United States’ strong and charismatic Cam F. Awesome had a superb 2014 where he won several European tournaments, which makes him a threat for gold in the heaviest weight division.

Brazil’s Rafael Lima won the gold medal at the Pan American Games Qualifier, and keep an eye out for Virgin Islands’ Clayton Laurent who won all of his three contests in Season V of WSB.

Last but not least, Canada’s London 2012 Olympic Games quarter-finalist Simon Kean will be fighting on home soil and is a dangerous opponent when on top form.