UK light-heavyweight Buatsi made a winning yet unimpressive debut to life under recent management with a decision win over Zach Parker in Manchester.
The Olympic bronze medallist's activity level seemingly secured him a split decision in a competitive 10-round fight at the Co-op Live Arena.
But the challenger found success, connecting with powerful clean blows in a fight where the techniques failed to mesh, with frequent clinching spoiling the contest.
The officials scored it 96-94 in favor to the winner, with the remaining official a 95-95.
"It wasn't my best showing but what do champions do? They win," the victor said in the ring as he was faced negative reactions from the audience.
The British fighter got back to winning after his initial pro loss - an thrilling contest with his previous opponent in last winter - to secure a twentieth professional win.
Some ringside observers believed the challenger, thirty-one, merited the victory but the contender suffered the second defeat of his 28-fight professional journey.
Buatsi Secures Win in Dull Encounter
The fighter's advancement has slowed in recent times through contract problems and long spells of inactivity.
Earlier forecast as the future of British boxing, he now is positioned trying to realize his potential - possibly in what feels like a final roll of the dice - under new promotional backing.
He started carefully, with the two boxers prepared to be aggressive in a tentative initial rounds.
The challenger, whose only previous defeat came at super middleweight against his former opponent in 2022 after suffering a hand injury in the contest, was participating in his second appearance at light heavyweight.
By the halfway stage, the underdog had kept it close, creating difficulties for the favorite, who worked behind a solid defense to barely take the better stanzas.
The spectators' acceptance wore thin amid regular grabbing, with the challenger falling to the floor various instances during close exchanges.
Parker finished the stronger, but many rounds were difficult to score. Nevertheless, former world champion the boxing analyst - providing analysis for Dazn - had it strongly leaning for Parker, scoring for Buatsi just a single round.
Buatsi progresses, but with the caliber of power puncher David Benavidez, and Russian champion Bivol ruling the division, the journey to titles - judging by this showing - still seems difficult.
Ricky Hatton Homage Fuels Manchester Derby Battle
In the supporting bout, Lyndon Arthur overcame Bradley Rea by divided decision in a terrific all-Manchester battle to secure the European light heavyweight title.
The stadium fell silent for a extremely emotional tribute prior to the bout as 10 bells tolled in memory of the city's native Ricky Hatton, who succumbed at age 46 in last month.
It was the premier televised fight night in the city since Hatton's passing. As the last bell disappeared, the quiet gave way to a shout of "only one Hatton".
The action during the bout equaled the sentiment. The eventual winner was floored by a powerful punch flush on the jaw in the second round, rising shakily to his feet on the count of eight.
But the Manchester United-red equipment of the fighter soon pressed ahead again. On the opposite side, Rea - in rival City blue - was damaged early, heavy swelling forming under his orbital area as the fighters landed hard punches.
The challenger, twenty-seven, delivered effective strikes but the champion, 34, responded in kind with effective uppercuts as the intensity rarely dropped over 12 rounds.
The victor edged the verdict with official scores of draw, 115-113 and clearer margin, but each competitor were determined and full of heart, all the qualities their idol the legend stood for.
