British light heavyweight Buatsi earned a win yet disappointing debut to life under new promoters with a decision win over Zach Parker in the Manchester arena.
The Olympic bronze medallist's punch output seemingly secured him a judges' verdict in a close ten-round fight at the Manchester venue.
But the challenger landed significant shots, connecting with powerful individual punches in a match where the approaches failed to mesh, with constant grabbing disrupting the action.
Two judges had it 96-94 for to the winner, with the third a even score.
"It wasn't my best performance but what do champions do? They succeed," the victor stated in the ring as he was met by boos from the spectators.
The Londoner got back to winning after his initial pro loss - an memorable fight with his previous opponent in last winter - to claim a twentieth professional win.
Some ringside observers believed the challenger, 31, merited the decision but the British boxer suffered the second setback of his 28-fight career.
The Champion Claims Victory in Uneventful Match
His career development has slowed in the past few years through promotional disputes and long spells of lack of fights.
Previously predicted as the rising talent of the British fight scene, he now stands trying to realize his potential - perhaps in what feels like a last chance - under fresh management.
He began cautiously, with the two boxers ready to overcommit in a calculated early stages.
Parker, whose single earlier setback came at super-middleweight against his former opponent in 2022 after breaking his hand mid-fight, was making just his second fight at light heavyweight.
By the fight's midpoint, the underdog had made it competitive, causing problems for Buatsi, who utilized a tight guard to narrowly win the more effective periods.
The audience's tolerance wore thin during regular grabbing, with Parker going down various instances during clinches.
The underdog finished the stronger, but several stanzas were challenging to assess. Nevertheless, former world champion Carl Frampton - working with Dazn - had it strongly leaning for the challenger, awarding Buatsi just one round.
The victor moves on, but with the presence of hard hitter Benavidez, and Eastern European fighter Dmitry Bivol leading the category, the journey to titles - on this evidence - still looks steep.
Hatton Memorial Motivates Local Rivalry Contest
In the secondary fight, Lyndon Arthur beat Rea by divided decision in a excellent Manchester vs Manchester battle to win the continental belt.
The venue grew hushed for a deeply poignant homage ahead of the contest as ten bells sounded in remembrance of Manchester's own Ricky Hatton, who died at age 46 in last month.
It was the premier televised boxing event in the location since Hatton's death. As the concluding sound faded, the silence transitioned to a chant of "there's only one Ricky Hatton".
The fighting during the bout equaled the emotion. Arthur was knocked down by a powerful punch squarely on the face in the initial stage, standing uncertainly to his footing on the count of eight.
But the red-colored equipment of Arthur soon came forward again. Across the ring, Rea - in opposing blue - was injured quickly, heavy swelling forming under his eye as the fighters traded punishing blows.
The challenger, twenty-seven, delivered effective strikes but Arthur, 34, fought fire with fire with effective uppercuts as the pace rarely dropped over 12 rounds.
Arthur barely secured the decision with judges scorecards of draw, close margin and clearer margin, but both fighters were relentless and brave, exactly what their inspiration Hatton stood for.
