UK light-heavyweight Buatsi secured a victory yet disappointing beginning to his career under new promoters with a unanimous decision 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 boxing arena.
But Parker landed significant shots, landing some telling clean blows in a fight where the techniques didn't complement each other, with excessive holding disrupting the contest.
Two judges scored it 96-94 for to the winner, with the third a even score.
"It wasn't my finest display but how do champions respond? They win," the victor commented in the arena as he was faced negative reactions from the audience.
The British fighter got back to winning after his maiden career setback - an memorable fight with his previous opponent in February - to earn a twentieth professional win.
Various analysts felt the challenger, 31, merited the decision but the Derbyshire fighter experienced the second defeat of his 28-bout professional journey.
Buatsi Secures Triumph in Dull Encounter
Buatsi's progress has slowed in recent years through management issues and long spells of inactivity.
Previously predicted as the next star of UK boxing, he now stands trying to realize his potential - possibly in what seems like a final roll of the dice - under recent support.
He started carefully, with neither fighter ready to be aggressive in a calculated early stages.
The challenger, whose only previous defeat came at the lower weight class against John Ryder in two years ago after suffering a hand injury mid-fight, was making just his second bout at light heavyweight.
By the middle rounds, Parker had stayed in contention, making life awkward for Buatsi, who worked behind a tight guard to edge the more effective rounds.
The audience's tolerance diminished amid constant clinching, with Parker falling to the floor multiple occasions during grappling.
The underdog ended stronger, but multiple periods were challenging to assess. However, previous titleholder the boxing analyst - providing analysis for Dazn - had it significantly in favor for Parker, scoring for Buatsi just one round.
Buatsi progresses, but with the caliber of power puncher Benavidez, and Eastern European fighter Bivol ruling the division, the path to championship success - on this evidence - still looks steep.
Hatton Tribute Inspires Manchester Derby Fight
In the secondary fight, Arthur overcame Bradley Rea by close verdict in a excellent local rivalry fight to win the continental championship.
The venue grew hushed for a extremely emotional tribute before the fight as a bell ceremony rang in honor of local hero Ricky Hatton, who passed away 46 years old in last month.
It was the premier televised fight night in the location since the passing of Hatton. As the final chime disappeared, the quiet became a shout of "there's just one Ricky Hatton".
The fighting within the ring reflected the feeling. Arthur was knocked down by a left hook flush on the chin in the second round, standing uncertainly to his position on the referee's count.
But the traditional red shorts of Arthur soon came forward again. On the opposite side, the opponent - in rival City blue - was marked up quickly, significant bruising forming under his eye as the fighters landed powerful shots.
The challenger, 27, delivered effective strikes but the champion, 34, responded in kind with powerful upward punches as the pace rarely dropped over twelve rounds.
Arthur edged the decision with scoring tallies of draw, 115-113 and clearer margin, but the two athletes were persistent and courageous, everything their inspiration the legend represented.
