UK light heavyweight Buatsi made a winning yet underwhelming debut to his career under recent management with a points victory over Zach Parker in the Manchester arena.
The Olympic bronze medallist's punch output appeared to earn him a majority decision in a tight 10-round fight at the Manchester venue.
But the challenger had his moments, delivering effective single shots in a contest where the approaches failed to mesh, with frequent clinching disrupting the action.
Two judges judged it 96-94 for to the winner, with the remaining official a 95-95 draw.
"It wasn't my best showing but what do champions do? They succeed," the victor stated in the ringside as he was met by negative reactions from the spectators.
The British fighter got back to winning after his maiden career setback - an thrilling contest with Callum Smith in last winter - to claim a twentieth professional win.
Several boxing experts believed the challenger, thirty-one, merited the victory but the contender suffered the second setback of his 28-bout career.
The Champion Secures Triumph in Slow Match
The fighter's advancement has plateaued in recent times through contract problems and long spells of inactivity.
Earlier forecast as the next star of the British fight scene, he now stands trying to realize his potential - maybe in what feels like a final roll of the dice - under new promotional backing.
He opened tentatively, with neither fighter prepared to overcommit in a cagey early stages.
The challenger, whose single earlier setback came at the lower weight class against his former opponent in 2022 after damaging his hand during the bout, was participating in his second appearance at light-heavyweight.
By the middle rounds, Parker had stayed in contention, making life awkward for Buatsi, who utilized a solid defense to barely take the more effective rounds.
The spectators' acceptance wore thin amid frequent holding, with the challenger falling to the floor various instances during grappling.
Parker ended stronger, but several stanzas were difficult to score. Although, previous titleholder the boxing analyst - working with the broadcast network - had it particularly wide for the challenger, giving Buatsi just a single round.
Buatsi advances, but with the caliber of power puncher David Benavidez, and Russian star Bivol leading the category, the journey to titles - judging by this showing - still looks steep.
Ricky Hatton Memorial Motivates All-Manchester Contest
In the supporting bout, Arthur overcame Rea by close verdict in a terrific all-Manchester fight to capture the European light-heavyweight championship.
The venue grew hushed for a deeply poignant tribute prior to the bout as a bell ceremony sounded in honor of local hero Hatton, who succumbed 46 years old in September.
It was the first major televised match card in the urban center since Hatton's death. As the concluding sound ended, the stillness became a chant of "there's only one Hatton".
The competition during the bout reflected the emotion. The eventual winner was floored by a left hook squarely on the chin in the early round, getting up unsteadily to his footing on the eight count.
But the traditional red equipment of Arthur soon advanced again. Across the ring, the opponent - in rival City blue - was injured early, noticeable damage forming under his eye as the fighters traded powerful shots.
The challenger, 27, delivered effective strikes but the champion, 34, matched the intensity with effective uppercuts as the intensity hardly diminished over twelve rounds.
Arthur barely secured the result with scoring tallies of even score, 115-113 and wider gap, but each competitor were persistent and courageous, everything their inspiration Hatton stood for.
