UK light heavyweight Buatsi secured a victory yet unimpressive debut to life under new promoters with a decision win over Zach Parker in the Manchester arena.
The Olympic bronze medallist's work rate appeared to earn him a majority decision in a competitive ten-round bout at the Manchester venue.
But Parker had his moments, delivering effective single shots in a match where the techniques never quite clicked, with excessive holding spoiling the fight.
The scoring judges judged it 96-94 for to Buatsi, with the remaining official a even score.
"It wasn't my greatest showing but what do champions do? They succeed," the victor commented in the arena as he was greeted with negative reactions from the crowd.
The British fighter got back to winning after his initial pro loss - an epic battle with his previous opponent in last winter - to secure a twentieth professional win.
Several boxing experts believed Parker, 31, should have been awarded the decision but the contender suffered the second loss of his 28-bout professional journey.
Buatsi Secures Win in Uneventful Match
His career development has plateaued in the past few years through contract problems and considerable time of inactivity.
Previously predicted as the future of British boxing, he now finds himself trying to fulfil that early promise - maybe in what appears to be a ultimate opportunity - under recent support.
He began cautiously, with the two boxers prepared to take risks in a calculated early stages.
The challenger, whose single earlier setback came at super-middleweight against John Ryder in 2022 after breaking his hand mid-fight, was participating in his second fight at light heavyweight.
By the halfway stage, Parker had kept it close, making life awkward for the favorite, who worked behind a solid defense to narrowly win the cleaner periods.
The crowd's patience decreased because of frequent holding, with the challenger falling to the floor several times during close exchanges.
Parker closed well, but several stanzas were hard to judge. Although, ex-champion Carl Frampton - providing analysis for the broadcast network - had it strongly leaning for the challenger, scoring for Buatsi just one round.
The victor advances, but with the caliber of hard hitter David Benavidez, and Russian star Dmitry Bivol dominating the weight class, the journey to titles - based on this performance - still appears challenging.
Hatton Memorial Fuels All-Manchester Battle
In the secondary fight, Arthur overcame Rea by divided decision in a outstanding all-Manchester battle to capture the European light heavyweight championship.
The stadium grew hushed for a profoundly moving memorial before the fight as ten bells sounded in honor of local hero Hatton, who passed away aged 46 in September.
It was the first major televised boxing event in the urban center since Hatton's death. As the concluding sound ended, the silence became a chant of "there's only one Ricky Hatton".
The fighting inside the ropes matched the sentiment. The eventual winner was knocked down by a left hook directly to the chin in the second round, rising shakily to his footing on the referee's count.
But the red-colored equipment of the fighter soon pressed ahead again. On the opposite side, the opponent - in competitive blue - was marked up quickly, significant bruising developing under his orbital area as the pair landed powerful shots.
The challenger, 27, connected with strong blows but the champion, 34, matched the intensity with effective uppercuts as the action rarely dropped over twelve rounds.
The victor barely secured the verdict with scoring tallies of 114-114, close margin and wider gap, but both fighters were relentless and full of heart, everything their inspiration the legend represented.
