Fighting in front of a hugely supportive audience in Hamburg, Harutyunyan was awarded the victory by split decision after 12 rounds of intense action.
Zakaryan had previously defeated the German twice in this competition and had only dropped two rounds in his APB career, but was surprisingly sluggish in the opening rounds.
Harutyunyan controlled the early action, where his fast left hands and creative body shots troubled the former Champion.
The Russian star rallied in the fifth round however, and also claimed the seventh frame as a result of his improved timing.
Although Harutyunyan dug deep to win the eighth round to quell the momentum from his opponent, from the ninth frame onwards the bout took a very different turn.
Zakaryan’s stamina was superior, and he controlled the penultimate three rounds of the contest with plenty of aggression and versatility in his shots.
With just one round to go, either man could still win the contest, but clearly inspired by the tremendous level of support at ringside, Harutyunyan produced an inspired final three minutes to ultimately secure a famous victory.
Surrounded by his friends and family, plus AIBA President Dr Ching-Kuo Wu and German Boxing Federation President Jurgen Kyas, Harutyunyan was awarded the prestigious APB Light Welterweight bout following his triumph.