By Jake Donovan

The Round of 16 for the Middleweight division gets underway in Day Six of Olympic boxing competition, and the party began in a very big way. Great Britain's own Anthony Ogogo pulled off the biggest upset of the tournament thus far with a double-tiebreaker win over Uzbekistan's Ievgen Khytrov.

Ogogo faced an uphill challenge from the moment he advanced to the Round of 16, drawing the defending World Amateur middleweight champion who received an opening round bye. The Brit was up for the task at hand, jumping out to an early lead as he received deafening levels of support from the rabid local crowd at Excel Arena in London. 

A two-point lead after one round was in jeopardy after Ogogo was gigged for two standing-eight counts in round two. Khyrtov turned up the heat considerably in the round, yet only managed a one-point margin in the frame to still trail by one heading into the final round.

Both fighters put it all on the line in the final three minutes. Ogogo attempted to box and move, while Khyrtov fight like a man who believed he needed a knockout in order to win. 

His train of thought wasn't very far off. The late surge managed to even things up at 18-18. A countback failed to break the tie, as the remaining judges' overall points total resulted in a 52-52 tally.

A final tiebreaker called for the five judges to press either the red or blue button to vote on which corner they believe won the fight. The majority of the panel selected "blue", which was good news for Ogogo, who now advances to the quarterfinals.

Khyrtov was one of five Ukraine fighters to receive an opening round bye. He is now just the second from the squad to be shown the exit. 

Ogogo will face Germany's Stefan Hartel in the quarterfinals. There existed the potential for a Great Britain v. Ireland matchup, but Hartel put that one to rest in topping Ireland's Darren O'Neill by a decisive 19-12 margin.

Zoltan Harcsa of Hungary moves within one fight of the medal round after taking a 16-7 verdict over Mjundjae Kasuto of Namibia. Harcsa was in lead for the entire fight, although Kasuto enjoyed a strong finish that might not have been properly reflected on the scorecards.

Nevertheless, the right fighter won as Harcsa moves on to Monday's quarterfinals. He will face Ezquiva Falcao of Brazil, who cruised through the Round of 16 with a 24-11 win over Soltan Migitinov of Azerbaijan. 

Falcao led every step of the way, building up an early lead and never taking his foot off the gas. Not even the comfort of a seven point lead through two rounds was enough for Falcao, who banged out a 9-3 final round to put an exclamation point on his performance.

The Olympic dream is a family affair for Falcao, whose brother Yamaguchi Falcao is still alive as he appears Saturday in light heavyweight Round of 16 action.  

Four more middleweight bouts are set for the evening portion of Day Six Olympic boxing competition. Team USA middleweight Terrell Gausha appears for the first time since his dramatic time-expired stoppage of Armenia's Andranik Hakobyan on Sunday. Awaiting the American in the Round of 16 is Vijender Singh, who captured Olympic bronze in the 2008 Beijing Games.

Middleweights - Round of 16 Matchups (Thursday, August 2):

Anthony Ogogo (Great Britain) def. Ievgen Khytrov (Ukraine), 18-18 (double tiebreaker)

Stefan Hartel (Germany) def. Darren O'Neill, 19-12

Zoltan Harcsa (Hungary) def. Mjundjae Kasuto (Namibia), 16-7

Ezquiva Falcao (Brazil) def. Soltan Migitinov (Azerbaijan), 24-11

Abbos Atoev (Uzbekistan) (Morocco) vs. Bogdan Juratoni (Romania/Received 1st round bye)

Terrell Gausha (USA) vs. Vijender Singh (India)

Adem Kılıççı (Turkey) vs.  Aleksander Drenovak (Serbia)

Abdelmalek Rahou (Algeria) vs. Ryota Murata (Japan/Received 1st round bye)

Middleweights Quarterfinals (Monday, August 6):

Anthony Ogogo (Great Britain) vs. Stefan Hartel (Germany)

Zoltan Harcsa (Hungary) vs. Ezquiva Falcao (Brazil) 

TBA vs. TBA

TBA vs. TBA

Middleweights - Round of 32 Results (Saturday, July 28):

Anthony Ogogo (Great Britain) def. Junior Castillo (Dominican Republic), 13-6

Darren O'Neill (Ireland) def. Muideen Akanji (Nigeria), 15-6

Stefan Hartel (Germany) def. Enrique Collazo (Puerto Rico), 18-10

Mjundjae Kasuto (Namibia) def. Sobirdzhon Inazarov (Tajikistan), 11-8

Zoltan Harcsa (Hungary) def. Jose Espinoza (Venezuela), 16-13

Soltan Migitinov (Azerbaijan) def. Mohamed Hikal (Egypt), 20-12

Abbos Atoev (Uzbekistan) def.  Badr-Eddine Haddioui (Morocco) – 11-9

Terrell Gausha (USA) def. Andranik Hakobyan (Armenia) - RSC-3

Vijender Singh (India) def. Danabek Suzhanov (Kazakhstan) - 14-10

Adem Kılıççı (Turkey) def. Nursahat Pazziyev (Turkmenistan) - 14-7

Aleksander Drenovak (Serbia) def. Mario Delgado (Ecuador) - 30-12

Abdelmalek Rahou (Algeria) def. Jesse Ross (Australia), 13-11

Jake Donovan is the Managing Editor of Boxingscene.com. Follow Jake on Twitter:

@JakeNDaBox