British light-heavyweight Buatsi secured a victory yet unimpressive debut to his career under new promoters with a decision win over Zach Parker in the Manchester arena.
The Olympic bronze medallist's punch output seemingly secured him a split decision in a tight ten-round fight at the boxing arena.
But the challenger had his moments, delivering effective individual punches in a match where the techniques never quite clicked, with constant grabbing disrupting the contest.
The scoring judges scored it 96-94 to Buatsi, with the third a 95-95.
"It wasn't my greatest display but what do champions do? They prevail," the victor commented in the ring as he was met by negative reactions from the audience.
The British fighter bounced back after his maiden career setback - an thrilling contest with Callum Smith in February - to earn a twentieth professional win.
Various analysts felt Parker, 31, should have been awarded the victory but the contender suffered the second setback of his 28-fight professional journey.
Buatsi Claims Win in Dull Encounter
The fighter's advancement has plateaued in recent times through contract problems and long spells of inactivity.
Earlier forecast as the next star of UK boxing, he now finds himself trying to realize his potential - perhaps in what feels like a ultimate opportunity - under recent support.
He opened tentatively, with both competitors willing to take risks in a tentative opening few rounds.
Parker, whose sole prior loss came at super-middleweight against John Ryder in 2022 after breaking his hand in the contest, was participating in his second appearance at the higher weight class.
By the middle rounds, the underdog had kept it close, causing problems for Buatsi, who operated with a tight guard to edge the more effective periods.
The spectators' acceptance wore thin because of frequent holding, with Parker falling to the floor several times during clinches.
Parker closed well, but multiple periods were difficult to score. Nevertheless, former world champion Carl Frampton - commentating on the broadcast network - had it particularly wide for Parker, giving Buatsi just only one stanza.
The victor progresses, but with the presence of power puncher David Benavidez, and Russian champion Bivol dominating the weight class, the path to championship success - judging by this showing - still seems difficult.
Hatton Tribute Inspires Local Rivalry Contest
In the secondary fight, Arthur overcame Rea by close verdict in a terrific local rivalry contest to win the European light-heavyweight championship.
The stadium fell silent for a profoundly moving tribute ahead of the contest as a bell ceremony sounded in memory of Manchester's own Ricky Hatton, who succumbed aged 46 in last month.
It was the first major televised fight night in the location since the passing of Hatton. As the final chime ended, the silence transitioned to a chant of "there's only one Ricky Hatton".
The action inside the ropes equaled the sentiment. Arthur was knocked down by a left hook squarely on the jaw in the second round, rising shakily to his position on the count of eight.
But the traditional red attire of Arthur soon came forward again. On the opposite side, Rea - in opposing blue - was marked up early, heavy swelling appearing under his eye as the fighters exchanged punishing blows.
The challenger, twenty-seven, connected with strong blows but the champion, 34, matched the intensity with effective uppercuts as the pace seldom decreased over the full distance.
Arthur narrowly won the decision with scoring tallies of 114-114, close margin and wider gap, but each competitor were relentless and brave, everything their inspiration the legend embodied.
