UK light-heavyweight Buatsi earned a win yet underwhelming beginning to his career under recent management with a points victory over Zach Parker in the Manchester arena.
The Olympic medal winner's work rate appeared to earn him a judges' verdict in a tight 10-round bout at the boxing arena.
But the challenger found success, connecting with powerful single shots in a fight where the techniques failed to mesh, with frequent clinching disrupting the fight.
The officials had it 96-94 in favor to Buatsi, with the remaining official a 95-95.
"It wasn't my best display but how do champions respond? They win," Buatsi commented in the arena as he was faced boos from the audience.
The British fighter got back to winning after his first professional defeat - an thrilling contest with his previous opponent in last winter - to secure a twentieth professional win.
Some ringside observers believed Parker, thirty-one, merited the victory but the contender endured the second loss of his 28-fight professional journey.
Buatsi Earns Triumph in Dull Encounter
Buatsi's progress has plateaued in recent years through contract problems and considerable time of inactivity.
Once tipped as the rising talent of British boxing, he now is positioned trying to achieve expectations - maybe in what appears to be a final roll of the dice - under fresh management.
He began cautiously, with both competitors prepared to take risks in a tentative initial rounds.
The challenger, whose sole prior loss came at super middleweight against John Ryder in 2022 after damaging his hand in the contest, was making just his second fight at light-heavyweight.
By the middle rounds, the underdog had stayed in contention, causing problems for the favorite, who utilized a solid defense to barely take the more effective stanzas.
The crowd's patience decreased amid constant clinching, with Parker slipping to the canvas multiple occasions during close exchanges.
Parker finished the stronger, but several stanzas were difficult to score. Although, former world champion Carl Frampton - working with the broadcast network - had it particularly wide for Parker, giving Buatsi just a single round.
Buatsi advances, but with the presence of hard hitter David Benavidez, and Russian star Dmitry Bivol leading the category, the road to world glory - judging by this showing - still looks steep.
Ricky Hatton Memorial Fuels All-Manchester Fight
In the secondary fight, Arthur beat Rea by close verdict in a terrific local rivalry fight to win the continental title.
The venue became quiet for a extremely emotional tribute prior to the bout as a bell ceremony sounded in memory of Manchester's own Ricky Hatton, who succumbed 46 years old in September.
It was the first major televised match card in the city since Hatton's death. As the final chime ended, the silence gave way to a shout of "only one Ricky Hatton".
The action inside the ropes equaled the feeling. Arthur was sent to the canvas by a powerful punch squarely on the face in the early round, standing uncertainly to his footing on the count of eight.
But the red-colored shorts of Arthur soon pressed ahead again. From the other corner, Rea - in opposing blue - was marked up soon, significant bruising forming under his face as the pair landed powerful shots.
The challenger, 27, landed power punches but Arthur, thirty-four, matched the intensity with effective uppercuts as the action hardly diminished over twelve rounds.
The victor edged the result with judges scorecards of even score, close margin and clearer margin, but the two athletes were relentless and brave, everything their hero Hatton stood for.
