British light-heavyweight Buatsi made a winning yet disappointing start to life under fresh promotional backing with a decision win over Zach Parker in the Manchester arena.
The Olympic bronze medallist's work rate likely gained him a judges' verdict in a close ten-round bout at the Co-op Live Arena.
But the challenger landed significant shots, connecting with powerful clean blows in a fight where the styles never quite clicked, with frequent clinching spoiling the fight.
The officials judged it 96-94 for to the winner, with the final judge a even score.
"It wasn't my finest showing but what defines champions? They succeed," the victor stated in the ringside as he was faced negative reactions from the spectators.
The British fighter bounced back after his first professional defeat - an epic battle with Callum Smith in February - to secure a 20th career victory.
Various analysts believed the challenger, thirty-one, merited the win but the contender endured the second defeat of his 28-fight professional journey.
Buatsi Secures Victory in Dull Match
Buatsi's progress has stalled in the past few years through promotional disputes and long spells of lack of fights.
Once tipped as the future of the British fight scene, he now finds himself trying to achieve expectations - perhaps in what seems like a ultimate opportunity - under recent support.
He opened tentatively, with both competitors willing to overcommit in a cagey initial rounds.
The challenger, whose only previous defeat came at super-middleweight against John Ryder in two years ago after breaking his hand mid-fight, was competing in only his second appearance at light-heavyweight.
By the halfway stage, Parker had made it competitive, creating difficulties for Buatsi, who worked behind a protective stance to narrowly win the better periods.
The spectators' acceptance wore thin during frequent holding, with Parker going down several times during grappling.
The underdog ended stronger, but many rounds were difficult to score. Nevertheless, former world champion Carl Frampton - providing analysis for Dazn - had it particularly wide for Parker, scoring for Buatsi just only one stanza.
Buatsi progresses, but with the likes of hard hitter Benavidez, and Russian star Dmitry Bivol leading the category, the path to championship success - based on this performance - still appears challenging.
Ricky Hatton Tribute Inspires Manchester Derby Contest
In the supporting bout, Arthur defeated Rea by divided decision in a excellent all-Manchester battle to capture the European light-heavyweight championship.
The arena fell silent for a profoundly moving tribute prior to the bout as ten bells tolled in remembrance of the city's native Hatton, who passed away aged 46 in last month.
It was the initial significant broadcast match card in the urban center since the passing of Hatton. As the concluding sound ended, the silence gave way to a chant of "only one Hatton".
The fighting within the ring reflected the emotion. The eventual winner was floored by a powerful punch flush on the face in the early round, rising shakily to his position on the eight count.
But the traditional red equipment of Arthur soon pressed ahead again. Across the ring, the opponent - in opposing blue - was damaged soon, significant bruising forming under his orbital area as the duo landed punishing blows.
The challenger, 27, landed power punches but the champion, 34, matched the intensity with effective uppercuts as the intensity hardly diminished over twelve rounds.
Arthur barely secured the decision with judges scorecards of 114-114, close margin and wider gap, but each competitor were persistent and full of heart, everything their hero Hatton represented.
