British light-heavyweight Buatsi made a winning yet underwhelming start to life under new promoters with a points victory over Zach Parker in Manchester.
The Olympic bronze medallist's punch output seemingly secured him a judges' verdict in a competitive 10-round contest at the boxing arena.
But the challenger landed significant shots, connecting with powerful single shots in a fight where the techniques failed to mesh, with constant grabbing spoiling the contest.
Two judges scored it 96-94 in favor to the winner, with the third a 95-95.
"It wasn't my greatest display but how do champions respond? They win," Buatsi said in the ring as he was faced disapproval from the audience.
The British fighter bounced back after his initial pro loss - an epic battle with his previous opponent in February - to secure a 20th career victory.
Some ringside observers believed Parker, 31, deserved the decision but the contender experienced the second defeat of his 28-match professional journey.
Buatsi Claims Victory in Uneventful Match
His career development has stalled in the past few years through management issues and extended periods of lack of fights.
Once tipped as the next star of the British fight scene, he now finds himself trying to achieve expectations - maybe in what appears to be a last chance - under fresh management.
He opened tentatively, with neither fighter willing to be aggressive in a calculated early stages.
Parker, whose single earlier setback came at super-middleweight against his former opponent in 2022 after suffering a hand injury mid-fight, was participating in his second appearance at the higher weight class.
By the halfway stage, Parker had stayed in contention, making life awkward for the favorite, who utilized a protective stance to edge the more effective rounds.
The crowd's patience diminished amid constant clinching, with Parker slipping to the canvas various instances during clinches.
Parker ended stronger, but many rounds were challenging to assess. Nevertheless, previous titleholder the boxing analyst - working with the broadcast network - had it particularly wide for the challenger, giving Buatsi just one round.
The victor advances, but with the caliber of power puncher David Benavidez, and Eastern European fighter Bivol ruling the division, the journey to titles - based on this performance - still appears challenging.
Ricky Hatton Homage Inspires Local Rivalry Battle
In the supporting bout, Lyndon Arthur beat Bradley Rea by divided decision in a outstanding all-Manchester contest to secure the European light heavyweight title.
The stadium became quiet for a deeply poignant tribute prior to the bout as a bell ceremony tolled in honor of Manchester's own Ricky Hatton, who succumbed 46 years old in recently.
It was the initial significant broadcast boxing event in the location since Hatton's death. As the last bell faded, the stillness transitioned to a roar of "there's just one Ricky Hatton".
The competition inside the ropes reflected the emotion. Arthur was sent to the canvas by a significant blow flush on the jaw in the early round, getting up unsteadily to his footing on the eight count.
But the red-colored equipment of the fighter soon advanced again. On the opposite side, the opponent - in rival City blue - was injured soon, significant bruising developing under his face as the fighters traded powerful shots.
The challenger, twenty-seven, landed power punches but the champion, 34, matched the intensity with effective uppercuts as the action hardly diminished over 12 rounds.
The victor barely secured the decision with official scores of 114-114, narrow lead and 115-112, but each competitor were relentless and brave, everything their idol the legend represented.
