British light-heavyweight Buatsi secured a victory yet unimpressive start to life under new promoters with a unanimous decision over Zach Parker in the Manchester arena.
The Olympic medal winner's punch output seemingly secured him a split decision in a close ten-round fight at the Manchester venue.
But the challenger had his moments, landing some telling single shots in a contest where the techniques failed to mesh, with constant grabbing marring the contest.
Two judges scored it 96-94 in favor to Buatsi, with the final judge a even score.
"It wasn't my finest performance but what defines champions? They win," the victor said in the ring as he was met by negative reactions from the crowd.
The British fighter bounced back after his initial pro loss - an epic battle with Callum Smith in last winter - to secure a 20th pro success.
Some ringside observers felt Parker, thirty-one, merited the victory but the contender suffered the second defeat of his 28-fight career.
Buatsi Secures Victory in Uneventful Affair
The fighter's advancement has stalled in the past few years through management issues and long spells of inactivity.
Once tipped as the next star of UK boxing, he now finds himself trying to achieve expectations - perhaps in what appears to be a last chance - under new promotional backing.
He opened tentatively, with the two boxers ready to be aggressive in a tentative early stages.
Parker, whose only previous defeat came at super middleweight against his former opponent in 2022 after breaking his hand in the contest, was competing in only his second fight at light heavyweight.
By the middle rounds, the underdog had made it competitive, causing problems for the favorite, who utilized a solid defense to narrowly win the more effective rounds.
The spectators' acceptance decreased amid constant clinching, with Parker falling to the floor various instances during clinches.
Parker closed well, but many rounds were difficult to score. However, previous titleholder Carl Frampton - commentating on Dazn - had it significantly in favor for Parker, scoring for Buatsi just one round.
Buatsi moves on, but with the likes of power puncher Benavidez, and Russian champion Dmitry Bivol dominating the weight class, the path to championship success - based on this performance - still appears challenging.
Ricky Hatton Homage Fuels All-Manchester Fight
In the co-main event, Arthur beat Bradley Rea by divided decision in a outstanding local rivalry battle to capture the European light-heavyweight championship.
The arena fell silent for a extremely emotional tribute ahead of the contest as ten bells rang in memory of local hero Hatton, who succumbed 46 years old in recently.
It was the premier televised match card in the urban center since Hatton's passing. As the concluding sound ended, the silence transitioned to a roar of "there's only one Ricky Hatton".
The action inside the ropes equaled the emotion. The eventual winner was floored by a significant blow squarely on the chin in the early round, getting up unsteadily to his feet on the count of eight.
But the red-colored shorts of Arthur soon came forward again. On the opposite side, the opponent - in competitive blue - was marked up early, significant bruising appearing under his face as the duo exchanged powerful shots.
Rea, twenty-seven, landed power punches but Arthur, thirty-four, fought fire with fire with powerful upward punches as the action hardly diminished over twelve rounds.
The victor edged the verdict with scoring tallies of 114-114, close margin and 115-112, but both fighters were persistent and full of heart, everything their inspiration the legend represented.
