UK light-heavyweight Buatsi made a winning yet underwhelming start to life under recent management with a decision win 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 found success, connecting with powerful clean blows in a fight where the styles didn't complement each other, with excessive holding disrupting the fight.
Two judges judged it 96-94 in favor to the winner, with the final judge a 95-95 draw.
"It wasn't my best showing but what do champions do? They succeed," the victor commented in the ring as he was met by boos from the audience.
The British fighter got back to winning after his first professional defeat - an epic battle with Callum Smith in last winter - to claim a twentieth professional win.
Various analysts felt the challenger, 31, merited the win but the contender experienced the second defeat of his 28-match career.
The Champion Earns Win in Slow Encounter
His career development has stalled in the past few years through contract problems and considerable time of inactivity.
Once tipped as the future of UK boxing, he now is positioned trying to realize his potential - possibly in what appears to be a ultimate opportunity - under recent support.
He opened tentatively, with neither fighter prepared to take risks in a calculated early stages.
The challenger, whose sole prior loss came at the lower weight class against John Ryder in 2022 after breaking his hand in the contest, was competing in only his second fight at light heavyweight.
By the halfway stage, Parker had stayed in contention, making life awkward for the favorite, who worked behind a protective stance to barely take the more effective periods.
The spectators' acceptance diminished because of frequent holding, with the challenger falling to the floor various instances during close exchanges.
The underdog closed well, but several stanzas were difficult to score. Nevertheless, previous titleholder the boxing analyst - providing analysis for the broadcast network - had it strongly leaning for Parker, awarding Buatsi just one round.
The victor advances, but with the caliber of hard hitter David Benavidez, and Russian champion Dmitry Bivol dominating the weight class, the road to world glory - judging by this showing - still seems difficult.
Ricky Hatton Memorial Fuels All-Manchester Contest
In the secondary fight, Arthur beat Bradley Rea by divided decision in a outstanding local rivalry battle to capture the European light-heavyweight championship.
The arena fell silent for a profoundly moving homage ahead of the contest as a bell ceremony tolled in memory of local hero Ricky Hatton, who passed away at age 46 in September.
It was the premier televised match card in the city since the passing of Hatton. As the final chime disappeared, the stillness transitioned to a roar of "there's just one Ricky Hatton".
The fighting inside the ropes reflected the sentiment. The eventual winner was sent to the canvas by a powerful punch flush on the chin in the second round, getting up unsteadily to his footing on the referee's count.
But the red-colored shorts of the fighter soon pressed ahead again. From the other corner, the opponent - in competitive blue - was marked up early, significant bruising appearing under his eye as the fighters traded powerful shots.
The challenger, 27, landed power punches but the champion, 34, matched the intensity with effective uppercuts as the action seldom decreased over twelve rounds.
Arthur barely secured the verdict with official scores of draw, close margin and clearer margin, but both fighters were persistent and full of heart, exactly what their hero Hatton embodied.
