British light heavyweight Buatsi earned a win yet unimpressive debut to his career under recent management with a unanimous decision over Zach Parker in the Manchester arena.
The Olympic medal winner's work rate likely gained him a majority decision in a competitive 10-round fight at the Manchester venue.
But the challenger found success, delivering effective single shots in a match where the approaches didn't complement each other, with excessive holding marring the fight.
Two judges scored it 96-94 for to the winner, with the remaining official a 95-95 draw.
"It wasn't my greatest showing but how do champions respond? They win," the victor stated in the arena as he was faced boos from the spectators.
The British fighter returned to winning ways after his maiden career setback - an epic battle with Callum Smith in February - to earn a 20th pro success.
Some ringside observers believed Parker, 31, deserved the decision but the Derbyshire fighter experienced the second setback of his 28-fight career.
The Champion Earns Victory in Slow Match
Buatsi's progress has plateaued in recent times through contract problems and considerable time of lack of fights.
Once tipped as the next star of UK boxing, he now stands trying to realize his potential - possibly in what feels like a ultimate opportunity - under new promotional backing.
He started carefully, with both competitors prepared to take risks in a tentative early stages.
Parker, whose sole prior loss came at the lower weight class against his former opponent in 2022 after breaking his hand in the contest, was making just his second bout at the higher weight class.
By the fight's midpoint, the underdog had stayed in contention, causing problems for Buatsi, who operated with a solid defense to narrowly win the more effective rounds.
The spectators' acceptance decreased during constant clinching, with Parker slipping to the canvas several times during close exchanges.
Parker ended stronger, but several stanzas were hard to judge. However, ex-champion Carl Frampton - commentating on Dazn - had it significantly in favor for the challenger, scoring for Buatsi just one round.
The victor progresses, but with the caliber of hard hitter David Benavidez, and Eastern European fighter Dmitry Bivol leading the category, the path to championship success - based on this performance - still appears challenging.
Ricky Hatton Tribute Inspires Local Rivalry Fight
In the secondary fight, Arthur overcame Rea by split-decision in a excellent local rivalry fight to win the European light heavyweight belt.
The stadium grew hushed for a deeply poignant homage ahead of the contest as 10 bells tolled in memory of the city's native Ricky Hatton, who passed away 46 years old in September.
It was the initial significant broadcast boxing event in the city since Hatton's passing. As the final chime disappeared, the quiet transitioned to a chant of "there's just one Ricky Hatton".
The action within the ring reflected the emotion. Arthur was sent to the canvas by a powerful punch directly to the jaw in the initial stage, rising shakily to his position on the referee's count.
But the red-colored shorts of the fighter soon advanced again. From the other corner, the opponent - in rival City blue - was damaged early, heavy swelling forming under his face as the pair exchanged punishing blows.
The challenger, twenty-seven, landed power punches but Arthur, thirty-four, matched the intensity with stinging uppercuts as the action seldom decreased over twelve rounds.
The victor barely secured the result with judges scorecards of draw, 115-113 and wider gap, but both fighters were relentless and brave, all the qualities their idol Hatton stood for.
