UK light-heavyweight Buatsi secured a victory yet underwhelming beginning to life under recent management with a decision win over Zach Parker in the Manchester arena.
The Olympic medal winner's work rate appeared to earn him a split decision in a tight 10-round bout at the Co-op Live Arena.
But the challenger had his moments, connecting with powerful clean blows in a contest where the styles failed to mesh, with frequent clinching marring the action.
Two judges judged it 96-94 to Buatsi, with the remaining official a 95-95 draw.
"It wasn't my best display but what defines champions? They win," the victor stated in the arena as he was met by boos from the spectators.
The British fighter got back to winning after his maiden career setback - an thrilling contest with his previous opponent in February - to claim a 20th career victory.
Some ringside observers felt Parker, 31, should have been awarded the decision but the Derbyshire fighter suffered the second loss of his 28-match career.
The Champion Secures Win in Dull Match
His career development has slowed in recent years through contract problems and considerable time of inactivity.
Previously predicted as the next star of UK boxing, he now finds himself trying to fulfil that early promise - maybe in what appears to be a ultimate opportunity - under fresh management.
He began cautiously, with both competitors willing to be aggressive in a tentative opening few rounds.
The challenger, whose sole prior loss came at super middleweight against his former opponent in two years ago after breaking his hand in the contest, was competing in only his second appearance at light-heavyweight.
By the halfway stage, the underdog had stayed in contention, creating difficulties for Buatsi, who utilized a tight guard to edge the cleaner rounds.
The crowd's patience wore thin during regular grabbing, with the challenger going down multiple occasions during close exchanges.
Parker ended stronger, but multiple periods were challenging to assess. Nevertheless, previous titleholder the boxing analyst - providing analysis for Dazn - had it strongly leaning for the challenger, giving Buatsi just a single round.
The victor advances, but with the presence of power puncher David Benavidez, and Russian star Bivol ruling the division, the journey to titles - based on this performance - still seems difficult.
Ricky Hatton Homage Motivates Manchester Derby Contest
In the secondary fight, Lyndon Arthur beat Bradley Rea by divided decision in a terrific all-Manchester fight to win the European light-heavyweight championship.
The stadium fell silent for a extremely emotional homage before the fight as 10 bells rang in honor of the city's native Ricky Hatton, who died at age 46 in recently.
It was the initial significant broadcast match card in the city since the passing of Hatton. As the final chime faded, the stillness transitioned to a chant of "there's just one Ricky Hatton".
The fighting inside the ropes equaled the emotion. The eventual winner was knocked down by a significant blow directly to the face in the early round, standing uncertainly to his footing on the count of eight.
But the red-colored equipment of the fighter soon pressed ahead again. On the opposite side, Rea - in opposing blue - was marked up quickly, noticeable damage developing under his eye as the fighters landed punishing blows.
The challenger, twenty-seven, connected with strong blows but Arthur, thirty-four, responded in kind with effective uppercuts as the intensity hardly diminished over the full distance.
Arthur narrowly won the result with scoring tallies of even score, narrow lead and clearer margin, but the two athletes were determined and full of heart, all the qualities their hero Hatton embodied.
