Galal Yafai extended Great Britain's impressive run in Tokyo, claiming a split decision win over Zambia's Patrick Chinyemba. Scores were 30-27, 30-27, 29-28 for Yafai and 29-28, 29-28 for Chinyemba in their Round of 16 battle Saturday evening at Kokugikan Arena in Tokyo. 

The win was a far cry from Yafai's explosive opening round feat, a third-round knockout of Armenia's Koryun Soghomonyan five days ago. Yafai delivered an explosive statement with the win but had to sweat out the decision on Saturday as Chinyemba proved to be tough and awkward. 

Yafai was credited with a second round knockdown when a right hand left Chinyemba buzzed. It was his best sequence in an otherwise close round, one which Chinyemba actually won on one card. 

There was little to choose from in the final three minutes, though Yafai enjoyed the better of just enough exchanges to prevail on three scorecards.

Yafai—whose older brothers Kal, a former WBA junior bantamweight titlist, and Gamal are pros—will go on to face divisional three-seed Yosbany Veitia.  The three-time Olympian from Cuba outclassed Tetteh Sulemanu (Ghana) over three rounds.

Scores were 30-27, 30-27, 30-26, 30-26 and 30-26 for Veitia, who represented Cuba in 2012 London and 2016 Rio. He is one of the few Cubans to appear in multiple Olympics but fail to medal, though he can change that luck in four days.

Gabriel Escobar (Spain) offered a tireless workrate in willing his way to victory over Daniel Asenov (Bulgaria). One judge had the bout 29-28 for Asenov, overruled by scores of 29-28 on the remaining four cards for Escobar in an entertaining preliminary round battle.

Escobar set a frenetic pace early in the bout, offering a grunt with every punch which came often and with knockout intentions. Asenov did his best to remain composed, proving to be the superior technician whenever the action shifted from a fight to a boxing match. 

An early lead was preserved by Escobar down the stretch, with Asenov winning the third and final round on four of the five scorecards but too far down for it to have made a difference in the end. 

Escobar will next face Saken Bibossinov (Kazakhstan) in a flyweight quarterfinal bout on August 3. 

Bibossinov gets the nod after eliminating number two-seed Billal Bennama (France). Scores were 29-28 across the board for Bibossinov, who landed the cleaner punches in effectively offsetting Bennama's awkward aggression. 

Shabhodikin Zoirov is one of four returning Olympians among an Uzbekistan team that brought 11 participants to Tokyo. The defending 2016 Olympic Gold medalist remains just one of four on that team still alive in competition, following his unanimous decision win over Daniel David Varela de Pina (Cape Verde).

Scores were 30-27 across the board for Zoirov, who outboxed Varela de Pina for the most part but still has yet to capture his 2016 form. The Uzbek was fortunate to avoid a knockdown call in round two but nevertheless advances to the quarterfinal round and is now one win away from a second medal.

Zoirov will next face Carlo Paalam, who continues the impressive run for Philippines following a three-round win over Algeria's Mohamed Flissi. Paalam won 30-27 on all five scorecards, as his crisper punching and superior hand speed was well reflected in the final scores.

Ryomei Tanaka is now one win away from guaranteeing hosting Japan its second medal and the first from the men's squad following a win over China's Jianguan Hu. Multiple cuts suffered by Hu forced the bout to be stopped at 1:51 of round two, going to the cards where Tanaka won by split decision.

Tanaka—whose younger brother is former three-division tiltist Kosei Tanaka—won by scores of 20-18 on three cards, losing by the same score on a fourth card and with the final card even. The Japanese flyweight got there by taking the fight to Hu, although his aggression came at a small price in having to settle for the amateur version of a technical decision.

The win gives hosting Japan an overall record of 10-2, while already guaranteed a medal at women's flyweight. Tanaka's quest for a flyweight medal will depend on his ability to get past perhaps the greatest amateur to come out of Colombia in Yuberjen Martinez, the 2016 Olympic Silver medalist who beat Amit Panghal (India) on four of the five scorecards. 

Jake Donovan is a senior writer for Twitter: @JakeNDaBox