British light heavyweight Buatsi secured a victory yet disappointing debut to his career under recent management with a decision win over Zach Parker in Manchester.
The Olympic bronze medallist's work rate seemingly secured him a judges' verdict in a close ten-round contest at the Co-op Live Arena.
But the challenger landed significant shots, delivering effective clean blows in a contest where the approaches didn't complement each other, with excessive holding disrupting the action.
The scoring judges scored it 96-94 to Buatsi, with the final judge a even score.
"It wasn't my greatest display but what do champions do? They succeed," Buatsi commented in the ringside as he was faced negative reactions from the crowd.
The Londoner bounced back after his first professional defeat - an thrilling contest with his previous opponent in February - to claim a 20th pro success.
Some ringside observers thought the challenger, thirty-one, should have been awarded the win but the British boxer suffered the second setback of his 28-bout professional journey.
Buatsi Claims Triumph in Dull Affair
Buatsi's progress has stalled in the past few years through contract problems and long spells of inactivity.
Earlier forecast as the future of the British fight scene, he now stands trying to achieve expectations - perhaps in what feels like a last chance - under recent support.
He began cautiously, with both competitors prepared to be aggressive in a tentative initial rounds.
The challenger, whose sole prior loss came at the lower weight class against his former opponent in 2022 after breaking his hand in the contest, was competing in only his second fight at light-heavyweight.
By the halfway stage, the underdog had kept it close, making life awkward for Buatsi, who worked behind a tight guard to narrowly win the more effective rounds.
The audience's tolerance decreased during frequent holding, with the challenger going down multiple occasions during grappling.
Parker finished the stronger, but multiple periods were difficult to score. Although, ex-champion the boxing analyst - commentating on the broadcast network - had it strongly leaning for Parker, giving Buatsi just one round.
Buatsi advances, but with the likes of power puncher David Benavidez, and Eastern European fighter Dmitry Bivol leading the category, the path to championship success - based on this performance - still seems difficult.
Ricky Hatton Tribute Inspires Manchester Derby Battle
In the supporting bout, Arthur beat Rea by divided decision in a excellent Manchester vs Manchester contest to secure the continental title.
The stadium grew hushed for a deeply poignant homage before the fight as a bell ceremony sounded in memory of Manchester's own Ricky Hatton, who succumbed aged 46 in last month.
It was the premier televised fight night in the location since Hatton's passing. As the final chime ended, the silence transitioned to a shout of "there's just one Hatton".
The action during the bout equaled the feeling. Arthur was sent to the canvas by a powerful punch squarely on the chin in the early round, getting up unsteadily to his footing on the eight count.
But the traditional red equipment of the fighter soon came forward again. From the other corner, Rea - in opposing blue - was injured early, heavy swelling forming under his face as the fighters exchanged punishing blows.
The challenger, twenty-seven, connected with strong blows but Arthur, thirty-four, matched the intensity with stinging uppercuts as the pace rarely dropped over 12 rounds.
The victor barely secured the verdict with judges scorecards of 114-114, narrow lead and 115-112, but the two athletes were relentless and courageous, exactly what their inspiration Hatton stood for.
