British light heavyweight Buatsi earned a win yet unimpressive start to life under new promoters with a decision win over Zach Parker in the Manchester arena.
The Olympic bronze medallist's activity level seemingly secured him a majority decision in a close ten-round fight at the Manchester venue.
But Parker landed significant shots, connecting with powerful clean blows in a contest where the styles never quite clicked, with frequent clinching spoiling the contest.
The officials had it 96-94 for to Buatsi, with the third a even score.
"It wasn't my greatest display but how do champions respond? They win," Buatsi commented in the ring as he was met by negative reactions from the spectators.
The Londoner bounced back after his maiden career setback - an memorable fight with Callum Smith in last winter - to secure a 20th pro success.
Some ringside observers thought the challenger, 31, deserved the win but the contender experienced the second defeat of his 28-match professional journey.
The Champion Secures Victory in Uneventful Affair
His career development has plateaued in recent years through contract problems and considerable time of lack of fights.
Earlier forecast as the rising talent of UK boxing, he now finds himself trying to fulfil that early promise - perhaps in what feels like a last chance - under fresh management.
He opened tentatively, with both competitors prepared to take risks in a calculated initial rounds.
The challenger, whose sole prior loss came at the lower weight class against John Ryder in 2022 after breaking his hand during the bout, was participating in his second fight at the higher weight class.
By the halfway stage, the underdog had made it competitive, creating difficulties for the favorite, who worked behind a protective stance to narrowly win the better stanzas.
The crowd's patience wore thin amid frequent holding, with Parker slipping to the canvas various instances during clinches.
Parker ended stronger, but many rounds were difficult to score. Nevertheless, previous titleholder Carl Frampton - working with Dazn - had it significantly in favor for Parker, giving Buatsi just one round.
Buatsi progresses, but with the caliber of heavy hitter David Benavidez, and Russian star Bivol leading the category, the path to championship success - judging by this showing - still seems difficult.
Hatton Tribute Inspires Manchester Derby Contest
In the co-main event, Lyndon Arthur defeated Bradley Rea by close verdict in a terrific all-Manchester fight to capture the European light-heavyweight belt.
The arena became quiet for a extremely emotional homage prior to the bout as ten bells rang in remembrance of Manchester's own Hatton, who passed away at age 46 in last month.
It was the initial significant broadcast match card in the city since Hatton's death. As the concluding sound faded, the silence gave way to a shout of "there's just one Hatton".
The action during the bout matched the sentiment. Arthur was knocked down by a powerful punch directly to the face in the initial stage, rising shakily to his feet on the count of eight.
But the red-colored shorts of Arthur soon pressed ahead again. From the other corner, the opponent - in competitive blue - was marked up early, noticeable damage developing under his eye as the duo landed hard punches.
Rea, 27, delivered effective strikes but Arthur, thirty-four, matched the intensity with powerful upward punches as the action seldom decreased over the full distance.
Arthur edged the decision with judges scorecards of even score, narrow lead and clearer margin, but the two athletes were determined and brave, exactly what their hero the legend embodied.
