UK light heavyweight Buatsi secured a victory yet unimpressive start to his career under recent management with a unanimous decision over Zach Parker in the Manchester arena.
The Olympic bronze medallist's activity level appeared to earn him a majority decision in a tight ten-round fight at the Co-op Live Arena.
But the challenger had his moments, delivering effective clean blows in a fight where the approaches never quite clicked, with excessive holding disrupting the contest.
The officials had it 96-94 for to Buatsi, with the third a even score.
"It wasn't my finest performance but how do champions respond? They prevail," the victor said in the ringside as he was faced boos from the crowd.
The Londoner bounced back after his initial pro loss - an memorable fight with his previous opponent in last winter - to secure a twentieth professional win.
Some ringside observers believed Parker, thirty-one, should have been awarded the decision but the contender suffered the second setback of his 28-fight career.
Buatsi Claims Win in Uneventful Match
The fighter's advancement has plateaued in the past few years through contract problems and extended periods of lack of fights.
Previously predicted as the next star of UK boxing, he now stands trying to fulfil that early promise - maybe in what appears to be a ultimate opportunity - under new promotional backing.
He opened tentatively, with both competitors ready to take risks in a cagey early stages.
Parker, whose single earlier setback came at the lower weight class against John Ryder in two years ago after breaking his hand in the contest, was competing in only his second fight at light heavyweight.
By the halfway stage, the underdog had stayed in contention, causing problems for the favorite, who utilized a protective stance to edge the better rounds.
The crowd's patience decreased amid constant clinching, with Parker going down multiple occasions during close exchanges.
The underdog finished the stronger, but several stanzas were difficult to score. Nevertheless, previous titleholder Carl Frampton - commentating on the broadcast network - had it strongly leaning for Parker, awarding Buatsi just one round.
Buatsi progresses, but with the presence of heavy hitter David Benavidez, and Russian star Dmitry Bivol leading the category, the road to world glory - judging by this showing - still appears challenging.
Hatton Tribute Motivates Manchester Derby Contest
In the secondary fight, Lyndon Arthur beat Bradley Rea by split-decision in a terrific Manchester vs Manchester battle to win the European light heavyweight championship.
The stadium grew hushed for a extremely emotional homage before the fight as a bell ceremony tolled in remembrance of the city's native Ricky Hatton, who succumbed 46 years old in September.
It was the initial significant broadcast match card in the location since Hatton's passing. As the concluding sound faded, the quiet transitioned to a chant of "only one Ricky Hatton".
The action inside the ropes matched the sentiment. The eventual winner was sent to the canvas by a powerful punch flush on the chin in the initial stage, rising shakily to his feet on the count of eight.
But the Manchester United-red shorts of the fighter soon came forward again. On the opposite side, Rea - in competitive blue - was injured quickly, heavy swelling developing under his orbital area as the pair traded punishing blows.
The challenger, twenty-seven, connected with strong blows but the champion, 34, matched the intensity with powerful upward punches as the action seldom decreased over the full distance.
Arthur narrowly won the decision with judges scorecards of 114-114, 115-113 and clearer margin, but both fighters were relentless and courageous, exactly what their inspiration Hatton stood for.
