Gamburyan, who won for the first time since April of 2010, notched scorecard tallies of 29-28 twice and 30-27 to improve to 12-7.
With the fight coming down to the third round, Gamburyan garnered the bout's biggest highlight when he landed a right head kick that staggered Omigawa (13-12-1). Gamburyan, who trains at Glendale Fighting Club along with Team Hayastan and SK Golden Boys, went in for the kill and landed two terrific overhand rights.
"The guy didn't even go down and Manny's a good puncher," said Edmond Tarverdyan of the Glendale Fighting Club, Gamburyan's striking coach and lead corner man. "[Omigawa's] got a chin."
Later in the final round, Omigawa fought back and seemed to even stun Gamburyan a bit on the feet and looked to secure a guillotine on a number of occasions, but Gamburyan was able to secure the round with a number of takedowns, including a final punctuating slam in which he deposited Omigawa on his head.
Nonetheless, after having lost his last two bouts via decision after he thought he'd won, Gamburyan still admitted he was apprehensive going to the cards.
"You're always nervous," Gamburyan said. "Even if you dominate."
Omigawa contended he should've got the win, but instead was dealt his second consecutive loss and the fourth setback in his last five fights.
"We knew he was the stronger fighter coming into this, so I trained to avoid the takedown and tried to keep moving. I planned on throwing straight left punches to keep the distance and I think it worked very well," Omigawa said. "I thought I won the first and third rounds, but it's his hometown. I should've gotten the decision."
Indeed, Gamburyan was the fan favorite, as he drew a loud ovation and some added motivation fighting a short drive from his North Hollywood home.