British light-heavyweight Buatsi secured a victory yet unimpressive beginning to his career under recent management with a unanimous decision over Zach Parker in Manchester.
The Olympic medal winner's work rate appeared to earn him a majority decision in a tight ten-round contest at the Co-op Live Arena.
But Parker had his moments, connecting with powerful clean blows in a contest where the styles failed to mesh, with excessive holding spoiling the fight.
Two judges judged it 96-94 for to the winner, with the remaining official a 95-95 draw.
"It wasn't my finest performance but how do champions respond? They prevail," the victor stated in the arena as he was greeted with disapproval from the crowd.
The British fighter got back to winning after his first professional defeat - an epic battle with Callum Smith in last winter - to claim a 20th pro success.
Some ringside observers felt Parker, thirty-one, deserved the victory but the contender experienced the second loss of his 28-match career.
Buatsi Earns Victory in Dull Encounter
His career development has slowed in the past few years through promotional disputes and considerable time of inactivity.
Once tipped as the next star of British boxing, he now stands trying to realize his potential - maybe in what appears to be a last chance - under new promotional backing.
He began cautiously, with neither fighter prepared to overcommit in a tentative initial rounds.
The challenger, whose only previous defeat came at super-middleweight against John Ryder in 2022 after breaking his hand mid-fight, was making just his second fight at light-heavyweight.
By the halfway stage, Parker had kept it close, causing problems for Buatsi, who utilized a tight guard to barely take the better periods.
The spectators' acceptance decreased during frequent holding, with the challenger going down several times during clinches.
The underdog closed well, but multiple periods were hard to judge. Although, previous titleholder the boxing analyst - providing analysis for Dazn - had it significantly in favor for the challenger, awarding Buatsi just a single round.
The victor moves on, but with the presence of power puncher David Benavidez, and Eastern European fighter Dmitry Bivol dominating the weight class, the path to championship success - judging by this showing - still looks steep.
Ricky Hatton Memorial Motivates Manchester Derby Contest
In the co-main event, Lyndon Arthur overcame Rea by divided decision in a outstanding local rivalry battle to capture the continental title.
The venue fell silent for a extremely emotional homage ahead of the contest as 10 bells tolled in honor of local hero Ricky Hatton, who succumbed aged 46 in September.
It was the initial significant broadcast match card in the urban center since the passing of Hatton. As the final chime faded, the silence transitioned to a roar of "there's just one Hatton".
The action within the ring equaled the feeling. Arthur was floored by a significant blow directly to the chin in the early round, standing uncertainly to his position on the eight count.
But the traditional red shorts of Arthur soon came forward again. From the other corner, the opponent - in rival City blue - was damaged quickly, heavy swelling appearing under his orbital area as the pair exchanged hard punches.
Rea, twenty-seven, landed power punches but the champion, 34, responded in kind with stinging uppercuts as the action rarely dropped over 12 rounds.
Arthur edged the decision with official scores of 114-114, narrow lead and 115-112, but both fighters were relentless and full of heart, all the qualities their hero the legend stood for.
