British light heavyweight Buatsi secured a victory yet underwhelming beginning to his career under fresh promotional backing with a unanimous decision over Zach Parker in the Manchester arena.
The Olympic bronze medallist's activity level appeared to earn him a split decision in a close ten-round contest at the boxing arena.
But the challenger landed significant shots, landing some telling individual punches in a contest where the techniques didn't complement each other, with excessive holding spoiling the action.
Two judges scored it 96-94 for to Buatsi, with the third a 95-95 draw.
"It wasn't my best performance but how do champions respond? They succeed," Buatsi said in the ring as he was met by boos from the spectators.
The British fighter bounced back after his first professional defeat - an epic battle with his previous opponent in February - to claim a 20th pro success.
Several boxing experts felt the challenger, thirty-one, should have been awarded the victory but the Derbyshire fighter endured the second defeat of his 28-bout professional journey.
Buatsi Secures Triumph in Dull Affair
Buatsi's progress has slowed in the past few years through promotional disputes and extended periods of inactivity.
Previously predicted as the rising talent of British boxing, he now finds himself trying to realize his potential - possibly in what appears to be a ultimate opportunity - under new promotional backing.
He began cautiously, with neither fighter willing to be aggressive in a tentative early stages.
The challenger, whose single earlier setback came at super-middleweight against his former opponent in 2022 after breaking his hand during the bout, was making just his second appearance at light heavyweight.
By the middle rounds, the underdog had kept it close, making life awkward for Buatsi, who operated with a solid defense to edge the better stanzas.
The spectators' acceptance diminished because of constant clinching, with the challenger slipping to the canvas several times during clinches.
Parker closed well, but several stanzas were difficult to score. However, previous titleholder Carl Frampton - working with Dazn - had it particularly wide for Parker, awarding Buatsi just only one stanza.
The victor progresses, but with the presence of power puncher David Benavidez, and Russian star Dmitry Bivol ruling the division, the road to world glory - on this evidence - still appears challenging.
Ricky Hatton Homage Motivates Manchester Derby Fight
In the co-main event, Arthur defeated Rea by close verdict in a outstanding all-Manchester contest to secure the continental belt.
The venue became quiet for a extremely emotional tribute before the fight as a bell ceremony rang in honor of Manchester's own Hatton, who died 46 years old in last month.
It was the first major televised fight night in the urban center since the passing of Hatton. As the concluding sound faded, the silence transitioned to a shout of "there's just one Ricky Hatton".
The fighting inside the ropes matched the feeling. The eventual winner was knocked down by a left hook flush on the jaw in the early round, standing uncertainly to his footing on the count of eight.
But the red-colored equipment of Arthur soon advanced again. From the other corner, Rea - in rival City blue - was injured early, significant bruising forming under his eye as the duo landed punishing blows.
Rea, 27, connected with strong blows but Arthur, 34, responded in kind with powerful upward punches as the action hardly diminished over twelve rounds.
The victor narrowly won the result with judges scorecards of draw, close margin and 115-112, but each competitor were determined and full of heart, all the qualities their hero Hatton embodied.
