UK light-heavyweight Buatsi made a winning yet underwhelming start to his career under fresh promotional backing with a decision win over Zach Parker in the Manchester arena.
The Olympic bronze medallist's punch output likely gained him a judges' verdict in a competitive 10-round fight at the Manchester venue.
But the challenger landed significant shots, delivering effective clean blows in a contest where the approaches failed to mesh, with frequent clinching disrupting the fight.
The officials judged it 96-94 in favor to Buatsi, with the third a 95-95.
"It wasn't my best performance but what defines champions? They win," Buatsi stated in the ring as he was met by boos from the crowd.
The British fighter bounced back after his first professional defeat - an epic battle with his previous opponent in February - to secure a twentieth professional win.
Various analysts felt the challenger, thirty-one, should have been awarded the win but the contender suffered the second loss of his 28-match professional journey.
Buatsi Earns Win in Uneventful Encounter
Buatsi's progress has slowed in the past few years through promotional disputes and extended periods of inactivity.
Once tipped as the rising talent of the British fight scene, he now is positioned trying to fulfil that early promise - possibly in what appears to be a final roll of the dice - under new promotional backing.
He started carefully, with neither fighter ready to be aggressive in a cagey opening few rounds.
The challenger, whose single earlier setback came at super-middleweight against his former opponent in two years ago after breaking his hand mid-fight, was competing in only 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 protective stance to edge the cleaner rounds.
The spectators' acceptance wore thin because of regular grabbing, with the challenger falling to the floor various instances during clinches.
The underdog ended stronger, but multiple periods were difficult to score. Although, former world champion the boxing analyst - providing analysis for Dazn - had it particularly wide for the challenger, scoring for Buatsi just a single round.
Buatsi moves on, but with the likes of power puncher David Benavidez, and Eastern European fighter Bivol ruling the division, the journey to titles - judging by this showing - still looks steep.
Ricky Hatton Tribute Motivates Manchester Derby Contest
In the co-main event, Arthur beat Bradley Rea by divided decision in a terrific local rivalry fight to secure the European light heavyweight title.
The venue grew hushed for a deeply poignant tribute ahead of the contest as 10 bells tolled in honor of the city's native Ricky Hatton, who succumbed aged 46 in last month.
It was the initial significant broadcast match card in the location since the passing of Hatton. As the final chime ended, the stillness transitioned to a chant of "there's only one Ricky Hatton".
The action inside the ropes equaled the emotion. The eventual winner was sent to the canvas by a significant blow flush on the face in the initial stage, rising shakily to his feet on the count of eight.
But the traditional red shorts of Arthur soon pressed ahead again. On the opposite side, the opponent - in opposing blue - was marked up soon, noticeable damage appearing under his orbital area as the duo exchanged powerful shots.
Rea, twenty-seven, landed power punches but the champion, thirty-four, responded in kind with stinging uppercuts as the action rarely dropped over the full distance.
Arthur narrowly won the result with judges scorecards of draw, narrow lead and 115-112, but each competitor were persistent and full of heart, all the qualities their inspiration the legend represented.
