Things are getting serious tonight in boxing as the first quarterfinals will take place in the bantamweight (56kg) and heavyweight (91kg) divisions. The winners tonight are guaranteed a place on the podium and a medal. The fights will start at 20:30 London time (15:30 EST)

Matchups:

Bantamweight:

Lazaro Alvarez Estrada (Cuba) vs Robenilson Vieira De Jesus (Brazil):

Reigning world champion Lazaro Alvarez is the favorite to take gold in this weight class. He had a bye in the round of 32 and beat Joseph Diaz Jr (USA) in the round of 16, Alvarez wasn't as dominant as he was expected to be in that fight (he dominated Diaz in the quarterfinals of the 2011 world championships) but I think Diaz deserves a lot of credit for that, he looked really improved.
Vieira beat Orzubek Shayimov (Uzbekistan) and Sergey Vodopiyanov (Russia) to get to the quarter finals. I
thought Vodopiyanov got jobbed in that fight and I don't think Vieira will cause much trouble to Alvarez.

My pick: Alvarez

John Joe Nevin (Ireland) vs Oscar Valdez Fierro (Mexico):

2011 world bronze medalist John Joe Nevin probably had the most impressive performances in this weight class so far with his dominant wins over Dennis Ceylan (Denmark) and Kanat Abutalipov while Valdez Fierro beat promising prospect Shiva Thapa (India) and upset top seed and 2011 world bronze medalist Anvar Yunusov (Tajikistan). This should be a very interesting fight, Nevin is the rightful favorite but I expect Valdez Fierro to make it a fight and wouldn't be overly surprised if he scored a second upset.

My pick: Nevin

Luke Campbell (Great Britain) vs Detelin Dalakliev (Bulgaria):

Campbell (2011 world silver medalist) is the favorite on this side of the bracket. He defeated a game Jahyn Vittorio Parinello in the round of 16, using his reach and solid boxing skills. Detelin Dalakliev (2009 world champion) is a solid boxer but at 29 years old, he seems to have declined a bit since his championship run. He easily defeated Ayabonga Sonjica of South Africa in the round of 32 but struggled against Ibrahim Balla (Australia) in his next fight, winning an extremely close decision to get to the quarterfinals.

My pick: Campbell

Mohamed Ouadahi (Algeria) vs Satoshi Shimizu (Japan):

Ouadahi advanced by walk over in the round of 32 and defeated William Encarnacion Alcantara (Dominican Republic) in the round of 16. Shimizu won a close decision in a pretty ugly fight against Isaac Dogboe in the round of 32 and took a beating in the first two rounds of his fight against top seed Magomed Abdulhimov (Azerbaidjan), Abdulhamidov gassed badly in the third and Shimizu made the most of his opportunity, battering the Azeri for the whole round. The problem was that he wasn't just fighting against him but also the ref and the judges, the ref never counted Abdulhamidov despite 5 knockdowns and the judges somehow scored that round even, awarding the win to Abdulhamidov in one of the most disgraceful decision I've ever seen. Thankfully, AIBA overturned the decision and Shimizu is in the quarterfinals. Honestly, neither of these guys was really impressive so far, Ouadahi's opponent fought a terrible fight and Shimizu seems unable to use his reach advantage effectively (prompting Wonderfulspam to nickname him the "Japanese Struve"). I'm leaning towards Ouadahi but I'd be extremely surprised to see one of these fighters winning their next fight.

My pick: Ouadahi

Heavyweight:

Unfortunately I missed the heavyweight fights and won't make picks but here are the match ups:

Oleksandr Usyk (Ukraine, 2008 world cup silver medalist, 2009 world silver medalist, 2011 world champion) vs Artur Beterbiev (Russia, 2007 world silver medalist, 2008 world cup gold medalist, 2009 world champion, all at LHW)

Tervel Pulev (Bulgaria) vs Yamil Peralta (Argentina)

Teymur Mammadov (Azerbaidjan) vs TBA

Jose Larduet (Cuba) vs Clemente Russo (ITA)