UK light-heavyweight Buatsi made a winning yet underwhelming debut to his career under new promoters with a points victory over Zach Parker in the Manchester arena.
The Olympic medal winner's activity level seemingly secured him a split decision in a competitive 10-round fight at the boxing arena.
But Parker found success, connecting with powerful clean blows in a contest where the approaches never quite clicked, with excessive holding disrupting the contest.
The scoring judges had it 96-94 for to the winner, with the third a even score.
"It wasn't my finest performance but what do champions do? They prevail," the victor commented in the arena as he was greeted with negative reactions from the crowd.
The British fighter returned to winning ways after his maiden career setback - an thrilling contest with Callum Smith in last winter - to secure a 20th pro success.
Several boxing experts felt Parker, thirty-one, deserved the win but the contender endured the second loss of his 28-match professional journey.
The Champion Claims Triumph in Uneventful Match
Buatsi's progress has stalled in recent times through contract problems and long spells of lack of fights.
Earlier forecast as the future of UK boxing, he now is positioned trying to fulfil that early promise - perhaps in what appears to be a last chance - under fresh management.
He opened tentatively, with neither fighter prepared to be aggressive in a tentative opening few rounds.
The challenger, whose single earlier setback came at super-middleweight against his former opponent in 2022 after breaking his hand in the contest, was participating in his second bout at light heavyweight.
By the fight's midpoint, Parker had made it competitive, causing problems for Buatsi, who worked behind a protective stance to edge the better periods.
The audience's tolerance diminished amid regular grabbing, with the challenger slipping to the canvas various instances during close exchanges.
The underdog closed well, but many rounds were hard to judge. However, previous titleholder Carl Frampton - providing analysis for Dazn - had it significantly in favor for Parker, awarding Buatsi just a single round.
The victor advances, but with the presence of heavy hitter David Benavidez, and Eastern European fighter Bivol leading the category, the path to championship success - based on this performance - still looks steep.
Hatton Memorial Fuels Local Rivalry Contest
In the secondary fight, Arthur overcame Bradley Rea by close verdict in a terrific all-Manchester fight to secure the continental title.
The arena grew hushed for a profoundly moving tribute ahead of the contest as ten bells tolled in remembrance of local hero Ricky Hatton, who died aged 46 in recently.
It was the initial significant broadcast boxing event in the urban center since Hatton's death. As the concluding sound disappeared, the silence became a shout of "there's only one Hatton".
The action during the bout equaled the sentiment. The eventual winner was sent to the canvas by a powerful punch flush on the chin in the initial stage, getting up unsteadily to his feet on the count of eight.
But the traditional red attire of the fighter soon advanced again. Across the ring, Rea - in rival City blue - was damaged early, heavy swelling forming under his orbital area as the pair traded punishing blows.
The challenger, twenty-seven, landed power punches but the champion, thirty-four, responded in kind with powerful upward punches as the action rarely dropped over twelve rounds.
The victor edged the result with scoring tallies of 114-114, 115-113 and clearer margin, but each competitor were relentless and full of heart, exactly what their inspiration Hatton stood for.
