UK light-heavyweight Buatsi earned a win yet underwhelming debut to life under recent management with a decision win over Zach Parker in the Manchester arena.
The Olympic bronze medallist's work rate appeared to earn him a split decision in a tight ten-round bout at the Manchester venue.
But the challenger had his moments, connecting with powerful single shots in a match where the techniques didn't complement each other, with excessive holding spoiling the action.
The officials scored it 96-94 in favor to Buatsi, with the third a 95-95.
"It wasn't my finest performance but how do champions respond? They prevail," Buatsi said in the arena as he was greeted with negative reactions from the crowd.
The British fighter got back to winning after his maiden career setback - an epic battle with his previous opponent in last winter - to secure a 20th pro success.
Various analysts thought the challenger, thirty-one, deserved the decision but the contender experienced the second defeat of his 28-match career.
The Champion Claims Win in Dull Match
Buatsi's progress has stalled in the past few years through contract problems and extended periods of lack of fights.
Earlier forecast as the next star of the British fight scene, he now is positioned trying to fulfil that early promise - maybe in what seems like a final roll of the dice - under recent support.
He began cautiously, with the two boxers ready to be aggressive in a tentative opening few rounds.
The challenger, whose single earlier setback came at super middleweight against his former opponent in 2022 after damaging his hand in the contest, was participating in his second bout at light-heavyweight.
By the middle rounds, Parker had made it competitive, causing problems for Buatsi, who utilized a solid defense to narrowly win the better stanzas.
The audience's tolerance wore thin amid constant clinching, with Parker falling to the floor multiple occasions during grappling.
The underdog ended stronger, but many rounds were difficult to score. Although, ex-champion the boxing analyst - working with Dazn - had it significantly in favor for the challenger, scoring for Buatsi just a single round.
Buatsi progresses, but with the likes of power puncher David Benavidez, and Russian star Bivol dominating the weight class, the journey to titles - based on this performance - still looks steep.
Ricky Hatton Tribute Inspires All-Manchester Contest
In the co-main event, Lyndon Arthur defeated Rea by close verdict in a excellent all-Manchester fight to capture the continental belt.
The stadium fell silent for a profoundly moving tribute prior to the bout as 10 bells sounded in honor of local hero Ricky Hatton, who died 46 years old in last month.
It was the first major televised fight night in the location since the passing of Hatton. As the final chime faded, the stillness gave way to a chant of "only one Ricky Hatton".
The fighting inside the ropes equaled the emotion. The eventual winner was knocked down by a left hook flush on the jaw in the initial stage, rising shakily to his position on the count of eight.
But the traditional red shorts of Arthur soon advanced again. From the other corner, Rea - in rival City blue - was injured soon, heavy swelling forming under his orbital area as the pair exchanged powerful shots.
Rea, 27, landed power punches but Arthur, thirty-four, matched the intensity with powerful upward punches as the action rarely dropped over twelve rounds.
The victor edged the verdict with scoring tallies of draw, close margin and clearer margin, but both fighters were persistent and brave, exactly what their idol Hatton embodied.
