British light heavyweight Buatsi made a winning yet unimpressive beginning to life under fresh promotional backing 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 contest at the Co-op Live Arena.
But Parker found success, delivering effective individual punches in a fight where the styles failed to mesh, with frequent clinching spoiling the fight.
The officials judged it 96-94 in favor to the winner, with the final judge a even score.
"It wasn't my greatest showing but how do champions respond? They prevail," the victor said in the arena as he was greeted with negative reactions from the audience.
The Londoner got back to winning after his first professional defeat - an memorable fight with Callum Smith in last winter - to claim a 20th pro success.
Several boxing experts thought the challenger, 31, should have been awarded the decision but the contender endured the second setback of his 28-match professional journey.
Buatsi Claims Win in Slow Affair
The fighter's advancement has plateaued in recent years through promotional disputes and long spells of inactivity.
Previously predicted as the future of UK boxing, he now finds himself trying to achieve expectations - perhaps in what seems like a last chance - under fresh management.
He began cautiously, with neither fighter ready to take risks in a tentative opening few rounds.
The challenger, whose single earlier setback came at super-middleweight against his former opponent in 2022 after damaging his hand mid-fight, was participating in his second fight at light-heavyweight.
By the fight's midpoint, the underdog had kept it close, creating difficulties for Buatsi, who utilized a protective stance to edge the cleaner rounds.
The spectators' acceptance diminished amid frequent holding, with Parker slipping to the canvas several times during clinches.
The underdog ended stronger, but several stanzas were hard to judge. However, previous titleholder Carl Frampton - working with Dazn - had it particularly wide for the challenger, scoring for Buatsi just only one stanza.
Buatsi progresses, but with the likes of power puncher Benavidez, and Russian star Bivol leading the category, the journey to titles - on this evidence - still seems difficult.
Hatton Homage Motivates Local Rivalry Fight
In the supporting bout, Arthur beat Bradley Rea by split-decision in a excellent Manchester vs Manchester contest to capture the European light-heavyweight championship.
The venue became quiet for a extremely emotional tribute prior to the bout as a bell ceremony tolled in honor of Manchester's own Ricky Hatton, who succumbed at age 46 in September.
It was the first major televised fight night in the location since Hatton's passing. As the final chime faded, the stillness became a chant of "only one Ricky Hatton".
The action during the bout equaled the emotion. Arthur was sent to the canvas by a powerful punch directly to the jaw in the second round, rising shakily to his position on the referee's count.
But the red-colored shorts of Arthur soon pressed ahead again. Across the ring, the opponent - in rival City blue - was damaged soon, significant bruising developing under his orbital area as the duo landed powerful shots.
Rea, twenty-seven, connected with strong blows but Arthur, 34, matched the intensity with effective uppercuts as the action hardly diminished over twelve rounds.
The victor barely secured the result with official scores of 114-114, close margin and 115-112, but each competitor were determined and full of heart, all the qualities their inspiration Hatton stood for.
