British light-heavyweight Buatsi made a winning yet underwhelming beginning to his career under fresh promotional backing with a points victory over Zach Parker in the Manchester arena.
The Olympic medal winner's work rate appeared to earn him a split decision in a competitive ten-round bout at the boxing arena.
But the challenger had his moments, connecting with powerful clean blows in a fight where the styles failed to mesh, with constant grabbing disrupting the contest.
Two judges judged it 96-94 for to the winner, with the final judge a 95-95 draw.
"It wasn't my finest display but what defines champions? They win," Buatsi said in the ringside as he was greeted with boos from the spectators.
The Londoner got back to winning after his maiden career setback - an epic battle with Callum Smith in last winter - to secure a twentieth professional win.
Some ringside observers thought the challenger, thirty-one, merited the decision but the British boxer experienced the second loss of his 28-match career.
Buatsi Claims Victory in Uneventful Match
Buatsi's progress has stalled in the past few years through promotional disputes and long spells of lack of fights.
Earlier forecast as the next star of British boxing, he now stands trying to achieve expectations - possibly in what seems like a final roll of the dice - under new promotional backing.
He opened tentatively, with the two boxers ready to be aggressive in a calculated early stages.
The challenger, whose single earlier setback came at super-middleweight against his former opponent in two years ago after suffering a hand injury mid-fight, was competing in only his second bout at light heavyweight.
By the middle rounds, Parker had stayed in contention, making life awkward for Buatsi, who operated with a tight guard to narrowly win the more effective stanzas.
The spectators' acceptance wore thin amid regular grabbing, with Parker falling to the floor several times during grappling.
The underdog finished the stronger, but multiple periods were hard to judge. Nevertheless, ex-champion the boxing analyst - commentating on the broadcast network - had it strongly leaning for Parker, giving Buatsi just only one stanza.
The victor moves on, but with the caliber of power puncher David Benavidez, and Russian star Dmitry Bivol ruling the division, the journey to titles - based on this performance - still seems difficult.
Hatton Memorial Motivates Manchester Derby Contest
In the supporting bout, Arthur defeated Rea by divided decision in a terrific Manchester vs Manchester battle to win the European light heavyweight belt.
The stadium fell silent for a extremely emotional memorial ahead of the contest as 10 bells rang in honor of local hero Hatton, who succumbed 46 years old in September.
It was the first major televised fight night in the city since the passing of Hatton. As the final chime disappeared, the silence transitioned to a chant of "there's just one Ricky Hatton".
The action during the bout reflected the sentiment. The eventual winner was floored by a left hook flush on the face in the early round, getting up unsteadily to his position on the referee's count.
But the Manchester United-red shorts of Arthur soon came forward again. Across the ring, the opponent - in rival City blue - was damaged early, significant bruising forming under his orbital area as the pair traded punishing blows.
The challenger, twenty-seven, delivered effective strikes but the champion, 34, responded in kind with powerful upward punches as the action seldom decreased over twelve rounds.
The victor barely secured the result with official scores of 114-114, 115-113 and wider gap, but each competitor were determined and courageous, exactly what their hero Hatton represented.
