The opening bell rang on the Rio 2016 Boxing Tournament on Saturday, with the opening bouts at Light Flyweight (49kg), Lightweight (60kg), Light Heavyweight (81kg) and Heavyweight (91kg) setting the tone for what is set to be a blistering competition over the coming 15 days.

A gripping opening bout saw Britain’s Galal Yafai, in-form going in to the Games, looking to get on the front foot against the winner of the African Continental Qualifier, Cameroon’s Simplice Fotsala. Fotsala responded well, landing strong uppercuts and combinations, but it was Yafai’s greater composure and dominance that impressed the judges, earning him a precious opening win and a second-round match-up against Cuba’s Johanys Argilagos.

Brazil’s Patrick Lourenço received a suitably warm welcome from the Rio crowd and looked to assert himself on Yurberjen Hern Martinez in an energetic start, but Colombia’s American Qualification Tournament winner was patient as he slowly unpicked Lourenço’s defences. A unanimous decision meant an early exit for Brazil’s first boxer of the Games, while Martinez will take great confidence into Monday’s second round match against Philippines’ Rogen Ladon.

The last Light Flyweight contest of the morning session saw Spain’s Samuel Carmona Heredia dominate his bout with the Armenian Artur Hovhannisyan, with a unanimous win that puts him into a second-round battle with Ireland’s three-time Olympian Patrick Barnes, bronze medallist in Beijing 2008 and London 2012.

The first Lightweight (60kg) bout of the day assumed historic significance, as Mexico’s Lindolfo Delgado faced-off against Italy’s experienced Carmine Tommasone, the first pro-boxer to take part in the Olympic Games as a result of the change to the AIBA statute on 1 June allowing non-AIBA athletes to compete. The Italian stalked his opponent around the ring, leaving Delgado little room to express himself, and Tommasone now meets the reigning World Champion, Cuba’s Lazaro Alvarez, in the second round.

Japan’s resilient, technically gifted Daisuke Narimatsu recovered well from Venezuelan Luis Cabrera’s early onslaught to earn a split decision and a match against USA’s Carlos Balderas. The American, ignited by a brilliant period of boxing from the middle of the second round against Kazakhstan’s Berik Abdrakhmanov, eventually won through in a memorable encounter.

A walkover saw Turkish Light Heavyweight (81kg) Mehmet Nadir Unal progress to a tough second-round tie against Cuban medal hope Julio Cesar La Cruz, before Croatia’s Hrvoje Sep edged a split decision against the Egyptian Abdelrahman Salah Orabi. By the time Brazil’s heavyweight (91kg) Juan Nogueira arrived in the ring to wrap up the first session of the Rio 2016 Boxing Competition, the packed Pavilion 6 arena was jumping. Several big Nogueira combinations closed out the first session in electrifying fashion, seeing him safely through to face Russian Evgeny Tishchenko on Monday morning and raising the roof in the process.

The evening session saw the Light Flyweights (49kg) Leandro Blanc of Argentina and experienced 23 year-old Mexican Joselito Velazquez begin proceedings, with Velazquez looking every bit a man back at his best form and ready to challenge for an Olympic medal. The 23 year-old Mexican star found his rhythm early on, replying quickly on the rare occasions that Blanc found a way through his defences to win by unanimous decision.

Velazquez will now meet Uzbekistan’s Hasanboy Dusmatov in the next round, while Namibia’s Mathias Hamunyela out-scored Azerbaijan’s 2014 Youth Olympic Champion Rufat Huseynov in one of the biggest surprises of the day. Both boxers flew out of their corners at the start of a breathless second round, but Hamunyela landed the cleaner blows to earn a unanimous decision and set up a duel with current World Champion Birzhan Zhakypov of Kazakhstan.

Rounding off the first day of Light Flyweight action, USA’s Nico Miguel Hernandez gradually found his way back into a tough contest with Italy’s Manuel Cappai, and will now take on the Russian second seed Vasilli Egorov on Monday evening.

Uzbekistan’s experienced Lightweight (60kg) Hurshid Tojibaev comfortably negotiated his opening-round tie against Qatari Hakan Eresker, setting up a second round match with Britain’s Joseph Cordina. The Brit was made to work hard for his win over Philippines’ busy Charly Coronel Suarez, but a strong last round would eventually see him safely through.

The Tajikstan and China teams then both had their first tastes of Rio 2016 action, and it was Anvar Yunusov who took the initiative and the first two rounds, leaving China’s Jun Shan’s frantic third-round burst too late to turn the tide.

Brazilian Light Heavyweight (81kg) Michel Borges received a hero’s welcome from the crowd as he entered the ring against veteran Cameroon pro Hassan Ndam Njikam, and was visibly lifted as he won the first two rounds, before powering on to a convincing win that will see him face Croatia’s morning session-winner Sep Hrvoje. In the second Light Heavyweight bout of the session, the big-hitting Colombian Juan Carlos Carrillo dominated proceedings against Kyrgyzstan’s Erkin Adylbek Uulu.

An entertaining first day of Rio 2016 boxing was completed by two big Heavyweight (91kg) talents; Britain’s European Qualifier winner Lawrence Okolie and Poland’s World Olympic Qualification Event winner Igor Pawel Jakubowski. Okolie landed some sharp punches early on, and the 24 year-old grew in confidence as the bout drew on, never looking troubled as he earned a testing second-round tie against Cuba’s imperious Erislandy Savon.