Eumir Marcial put his pro career on hold in order to leave his mark on amateur boxing's highest stage. 

The Manny Pacquiao-promoted representative of Philippines advances to the semifinal round of the men's middleweight division following a first-round knockout of Armenia's Arman Darchinyan. A right hook put Darchinyan down and out at 2:11 of round one. 

Marcial—who turned pro live on FS1 last November—has yet to be extended beyond the first round in either of his two Olympic bouts. The all-action Filipino left an impression after forcing a first-round stoppage of Algeria's Younes Nemouchi in their Round of 16 bout on Thursday. 

Nemouchi lasted just 2:41 in that fight—or 30 seconds longer than Darchinyan, as it would turn out. 

Darchinyan—the nephew of former two-division champion Vic Darchinyan—advanced to this point following a three-round decision over Andrej Csemez on Thursday. He never had a chance to get going on Sunday, as Marcial came out throwing heat and not looking to stop until he got the knockout he sought.

It would come barely two minutes into the first round. A right hook left Darchinyan vulnerable and wide open for an ensuing right hook behind the ear to send the Armenian crashing to the canvas, producing the stoppage win.

Marcial entered Tokyo as the number-one seed. He will now face the number-one seed, as Ukraine's Oleksandr Khyzhniak did his part following a decision win over Dominican Republic's Euri Cedeno.

Hebert Sousa (Brazil) delivered one of the tournament's more memorable performances—and post-fight celebrations—following a hard-fought win over Abilkhan Amakul (Kazakhstan). The Brazilian will go on to face Gleb Bakshi (ROC), who ended the Olympic medal dream of Darrelle Valsaint Jr. (Haiti) after winning on all five scorecards. 

Jake Donovan is a senior writer for Twitter: @JakeNDaBox