British light-heavyweight Buatsi secured a victory yet unimpressive beginning to life under recent management with a points victory over Zach Parker in Manchester.
The Olympic medal winner's punch output appeared to earn him a split decision in a competitive 10-round bout at the boxing arena.
But the challenger landed significant shots, landing some telling single shots in a contest where the approaches failed to mesh, with constant grabbing marring the action.
The scoring judges judged it 96-94 in favor to Buatsi, with the remaining official a 95-95.
"It wasn't my finest showing but how do champions respond? They win," Buatsi stated in the ring as he was faced negative reactions from the spectators.
The Londoner bounced back after his maiden career setback - an thrilling contest with his previous opponent in last winter - to earn a 20th career victory.
Various analysts believed Parker, thirty-one, should have been awarded the decision but the British boxer experienced the second defeat of his 28-bout career.
The Champion Secures Victory in Dull Match
The fighter's advancement has plateaued in recent times through contract problems and considerable time of lack of fights.
Earlier forecast as the rising talent of UK boxing, he now is positioned trying to achieve expectations - perhaps in what appears to be a last chance - under fresh management.
He started carefully, with both competitors willing to be aggressive in a calculated opening few rounds.
Parker, whose only previous defeat came at super-middleweight against his former opponent in 2022 after breaking his hand mid-fight, was making just his second appearance at the higher weight class.
By the halfway stage, Parker had made it competitive, causing problems for Buatsi, who worked behind a tight guard to barely take the cleaner rounds.
The spectators' acceptance diminished during constant clinching, with Parker slipping to the canvas multiple occasions during close exchanges.
The underdog finished the stronger, but several stanzas were difficult to score. Nevertheless, ex-champion Carl Frampton - commentating on the broadcast network - had it strongly leaning for Parker, giving Buatsi just only one stanza.
Buatsi moves on, but with the caliber of heavy hitter David Benavidez, and Russian star Dmitry Bivol ruling the division, the path to championship success - on this evidence - still looks steep.
Ricky Hatton Homage Fuels All-Manchester Battle
In the secondary fight, Lyndon Arthur beat Bradley Rea by close verdict in a outstanding local rivalry contest to win the continental title.
The stadium grew hushed for a deeply poignant tribute before the fight as a bell ceremony tolled in memory of the city's native Ricky Hatton, who succumbed at age 46 in recently.
It was the initial significant broadcast boxing event in the city since Hatton's death. As the last bell ended, the silence transitioned to a chant of "only one Hatton".
The competition within the ring reflected the sentiment. Arthur was sent to the canvas by a left hook flush on the face in the initial stage, standing uncertainly to his position on the referee's count.
But the Manchester United-red equipment of the fighter soon pressed ahead again. On the opposite side, the opponent - in competitive blue - was injured quickly, heavy swelling forming under his eye as the duo landed powerful shots.
Rea, 27, connected with strong blows but Arthur, 34, matched the intensity with effective uppercuts as the pace hardly diminished over the full distance.
Arthur barely secured the result with judges scorecards of 114-114, close margin and clearer margin, but both fighters were determined and brave, everything their inspiration Hatton stood for.
