British light heavyweight Buatsi secured a victory yet disappointing beginning to his career under new promoters with a points victory over Zach Parker in the Manchester arena.
The Olympic medal winner's punch output likely gained him a split decision in a competitive ten-round bout at the boxing arena.
But Parker found success, delivering effective single shots in a match where the approaches failed to mesh, with excessive holding disrupting the action.
Two judges scored it 96-94 to the winner, with the remaining official a even score.
"It wasn't my best performance but how do champions respond? They prevail," Buatsi stated in the ring as he was faced negative reactions from the audience.
The British fighter got back to winning after his maiden career setback - an memorable fight with Callum Smith in February - to claim a twentieth professional win.
Several boxing experts believed the challenger, 31, deserved the decision but the British boxer experienced the second loss of his 28-fight professional journey.
Buatsi Secures Triumph in Uneventful Match
His career development has plateaued in recent years through management issues and extended periods of inactivity.
Earlier forecast as the next star of British boxing, he now is positioned trying to achieve expectations - possibly in what appears to be a final roll of the dice - under new promotional backing.
He began cautiously, with the two boxers ready to be aggressive in a tentative initial rounds.
Parker, whose only previous defeat came at the lower weight class against John Ryder in 2022 after suffering a hand injury mid-fight, was making just his second fight at the higher weight class.
By the middle rounds, Parker had made it competitive, making life awkward for Buatsi, who worked behind a solid defense to edge the more effective rounds.
The audience's tolerance decreased amid regular grabbing, with the challenger falling to the floor multiple occasions during clinches.
Parker ended stronger, but multiple periods were difficult to score. Although, ex-champion Carl Frampton - commentating on the broadcast network - had it particularly wide for Parker, giving Buatsi just one round.
The victor moves on, but with the likes of power puncher David Benavidez, and Russian star Dmitry Bivol dominating the weight class, the road to world glory - based on this performance - still appears challenging.
Hatton Homage Motivates Manchester Derby Battle
In the secondary fight, Lyndon Arthur overcame Bradley Rea by close verdict in a terrific Manchester vs Manchester fight to win the European light-heavyweight championship.
The arena grew hushed for a deeply poignant tribute before the fight as 10 bells tolled in memory of local hero Ricky Hatton, who passed away aged 46 in September.
It was the first major televised match card in the city since the passing of Hatton. As the final chime faded, the quiet became a roar of "there's just one Ricky Hatton".
The competition inside the ropes matched the feeling. Arthur was sent to the canvas by a significant blow squarely on the face in the early round, getting up unsteadily to his feet on the count of eight.
But the traditional red shorts of the fighter soon pressed ahead again. Across the ring, Rea - in competitive blue - was damaged soon, significant bruising forming under his eye as the fighters exchanged punishing blows.
Rea, twenty-seven, delivered effective strikes but the champion, 34, matched the intensity with effective uppercuts as the pace seldom decreased over 12 rounds.
The victor narrowly won the result with judges scorecards of even score, 115-113 and wider gap, but both fighters were relentless and full of heart, all the qualities their idol Hatton stood for.
