British light-heavyweight Buatsi earned a win yet unimpressive debut to life under fresh promotional backing with a decision win over Zach Parker in the Manchester arena.
The Olympic medal winner's work rate likely gained him a judges' verdict in a tight ten-round bout at the boxing arena.
But Parker landed significant shots, landing some telling individual punches in a match where the techniques didn't complement each other, with constant grabbing spoiling the contest.
Two judges had it 96-94 to the winner, with the final judge a 95-95.
"It wasn't my finest display but how do champions respond? They win," Buatsi commented in the ringside as he was faced boos from the audience.
The Londoner bounced back after his first professional defeat - an thrilling contest with his previous opponent in last winter - to claim a 20th career victory.
Some ringside observers believed Parker, 31, merited the win but the British boxer endured the second setback of his 28-bout professional journey.
The Champion Secures Triumph in Uneventful Encounter
Buatsi's progress has plateaued in recent times through contract problems and considerable time of lack of fights.
Once tipped as the next star of the British fight scene, he now stands trying to realize his potential - possibly in what appears to be a last chance - under new promotional backing.
He opened tentatively, with both competitors prepared to be aggressive in a calculated initial rounds.
Parker, whose only previous defeat came at super middleweight against his former opponent in 2022 after suffering a hand injury mid-fight, was participating in his second fight at the higher weight class.
By the halfway stage, the underdog had made it competitive, creating difficulties for the favorite, who utilized a solid defense to barely take the cleaner periods.
The spectators' acceptance decreased amid regular grabbing, with the challenger slipping to the canvas several times during grappling.
Parker ended stronger, but several stanzas were challenging to assess. However, previous titleholder the boxing analyst - working with Dazn - had it significantly in favor for Parker, giving Buatsi just only one stanza.
The victor progresses, but with the presence of power puncher David Benavidez, and Eastern European fighter Dmitry Bivol dominating the weight class, the road to world glory - based on this performance - still looks steep.
Hatton Memorial Motivates All-Manchester Battle
In the secondary fight, Arthur overcame Rea by close verdict in a excellent Manchester vs Manchester fight to win the continental title.
The venue became quiet for a deeply poignant tribute prior to the bout as a bell ceremony rang in honor of Manchester's own Ricky Hatton, who died at age 46 in September.
It was the initial significant broadcast fight night in the urban center since Hatton's death. As the final chime disappeared, the stillness gave way to a chant of "there's just one Hatton".
The action within the ring reflected the emotion. The eventual winner was knocked down by a powerful punch squarely on the jaw in the early round, standing uncertainly to his position on the count of eight.
But the traditional red equipment of Arthur soon pressed ahead again. From the other corner, the opponent - in rival City blue - was injured quickly, significant bruising appearing under his face as the duo traded powerful shots.
Rea, 27, delivered effective strikes but Arthur, 34, matched the intensity with stinging uppercuts as the pace seldom decreased over 12 rounds.
The victor barely secured the result with judges scorecards of draw, narrow lead and wider gap, but the two athletes were determined and full of heart, exactly what their inspiration Hatton represented.
