UK light-heavyweight Buatsi made a winning yet disappointing start to his career under recent management with a points victory over Zach Parker in the Manchester arena.
The Olympic medal winner's activity level appeared to earn him a judges' verdict in a competitive 10-round contest at the boxing arena.
But the challenger found success, landing some telling clean blows in a match where the techniques didn't complement each other, with frequent clinching marring the action.
Two judges scored it 96-94 for to the winner, with the third a even score.
"It wasn't my greatest performance but what defines champions? They succeed," the victor commented in the ring as he was greeted with disapproval from the crowd.
The British fighter bounced back after his maiden career setback - an memorable fight with Callum Smith in last winter - to secure a twentieth professional win.
Several boxing experts felt Parker, 31, merited the win but the British boxer experienced the second setback of his 28-match professional journey.
Buatsi Earns Victory in Slow Match
Buatsi's progress has slowed in the past few years through management issues and extended periods of lack of fights.
Once tipped as the next star of British boxing, he now finds himself trying to realize his potential - maybe in what seems like a ultimate opportunity - under recent support.
He opened tentatively, with neither fighter prepared to overcommit in a calculated opening few rounds.
Parker, whose only previous defeat came at the lower weight class against his former opponent in 2022 after damaging his hand in the contest, was making just his second appearance at light-heavyweight.
By the halfway stage, Parker had made it competitive, making life awkward for Buatsi, who utilized a tight guard to narrowly win the cleaner periods.
The audience's tolerance diminished because of frequent holding, with Parker going down several times during grappling.
The underdog closed well, but multiple periods were difficult to score. Nevertheless, ex-champion Carl Frampton - providing analysis for the broadcast network - had it strongly leaning for the challenger, giving Buatsi just one round.
The victor advances, but with the caliber of hard hitter David Benavidez, and Russian star Dmitry Bivol ruling the division, the path to championship success - judging by this showing - still looks steep.
Ricky Hatton Homage Fuels Local Rivalry Contest
In the supporting bout, Arthur beat Rea by split-decision in a excellent all-Manchester fight to secure the European light heavyweight belt.
The venue grew hushed for a deeply poignant tribute before the fight as 10 bells sounded in honor of Manchester's own Hatton, who died at age 46 in last month.
It was the initial significant broadcast boxing event in the urban center since the passing of Hatton. As the final chime disappeared, the quiet transitioned to a roar of "there's only one Hatton".
The fighting during the bout matched the sentiment. The eventual winner was floored by a powerful punch squarely on the face in the initial stage, standing uncertainly to his position on the referee's count.
But the Manchester United-red shorts of the fighter soon pressed ahead again. On the opposite side, Rea - in competitive blue - was damaged soon, significant bruising developing under his eye as the duo landed hard punches.
The challenger, twenty-seven, landed power punches but Arthur, thirty-four, matched the intensity with effective uppercuts as the action seldom decreased over the full distance.
The victor edged the decision with scoring tallies of 114-114, close margin and wider gap, but the two athletes were relentless and brave, everything their inspiration the legend represented.
