Last time out, Marsters caught Nyika off-guard with an opening round barrage.
The Australian deployed the same tactics in the opening seconds, but Nyika managed to weather the storm, cutting him off with a couple of good shots as his opponent looked to move in.
WBC heavyweight champion Tyson Fury could be heard coaching Nyika at ringside, telling the Olympic bronze medallist to establish his jab; the Kiwi obliged when he switched to his orthodox stance.
Fighting southpaw, Nyika found success with the left hook.
The crowd cheered when UFC middleweight champion Israel Adesanya was shown ringside, with Nyika receiving a high-five from the mixed martial artist at the conclusion of the bout.
After a frustrating layoff, Nyika will be looking to continue the momentum from this win as he looks to build his professional career.
Speaking to the Herald last week, Nyika said he was hopeful of a quick turnaround - with hopes of picking up another two fights in the next couple of months.
“We’re trying to line up one for four weeks after this and another one four weeks after that,” he said.
“I just want to get back in the ring and get in front of big crowds again, because you can forget so quickly what that means to you just being away from it.
“Once you get under the lights, you get that hunger again and you just want to get after it time and time again. It’s addictive and if you haven’t experienced that, you wouldn’t understand it.
“It’s a real rush. I’m not an adrenaline junkie, but once boxing gets in your veins, it’s really hard to get out.”