British light-heavyweight Buatsi made a winning yet unimpressive debut to his career under recent management with a decision win over Zach Parker in Manchester.
The Olympic bronze medallist's activity level likely gained him a judges' verdict in a close ten-round fight at the Co-op Live Arena.
But the challenger found success, connecting with powerful clean blows in a match where the approaches never quite clicked, with constant grabbing spoiling the action.
The officials scored it 96-94 in favor to Buatsi, with the third a 95-95.
"It wasn't my greatest showing but what defines champions? They succeed," the victor commented in the ringside as he was greeted with disapproval from the audience.
The Londoner returned to winning ways after his first professional defeat - an epic battle with his previous opponent in last winter - to secure a twentieth professional win.
Some ringside observers believed the challenger, thirty-one, should have been awarded the win but the Derbyshire fighter experienced the second loss of his 28-bout professional journey.
Buatsi Secures Victory in Uneventful Encounter
His career development has stalled in recent times through contract problems and extended periods of lack of fights.
Previously predicted as the next star of UK boxing, he now stands trying to realize his potential - maybe in what appears to be a final roll of the dice - under recent support.
He opened tentatively, with both competitors willing 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 during the bout, was competing in only his second bout at the higher weight class.
By the fight's midpoint, the underdog had kept it close, creating difficulties for Buatsi, who worked behind a solid defense to narrowly win the more effective stanzas.
The crowd's patience decreased amid regular grabbing, with Parker slipping to the canvas various instances during close exchanges.
Parker closed well, but several stanzas were challenging to assess. However, previous titleholder Carl Frampton - commentating on Dazn - had it particularly wide for Parker, awarding Buatsi just one round.
Buatsi progresses, but with the caliber of power puncher Benavidez, and Eastern European fighter Dmitry Bivol ruling the division, the journey to titles - based on this performance - still appears challenging.
Ricky Hatton Memorial Fuels Manchester Derby Battle
In the secondary fight, Arthur beat Bradley Rea by close verdict in a excellent all-Manchester battle to secure the continental championship.
The arena grew hushed for a deeply poignant memorial prior to the bout as ten bells sounded in memory of the city's native Ricky Hatton, who died aged 46 in September.
It was the premier televised fight night in the urban center since the passing of Hatton. As the concluding sound faded, the stillness became a roar of "only one Hatton".
The competition within the ring reflected the emotion. Arthur was floored by a significant blow flush on the face in the initial stage, rising shakily to his position on the referee's count.
But the Manchester United-red shorts of the fighter soon came forward again. From the other corner, the opponent - in competitive blue - was injured early, heavy swelling developing under his eye as the duo landed hard punches.
Rea, 27, delivered effective strikes but the champion, thirty-four, matched the intensity with effective uppercuts as the action hardly diminished over 12 rounds.
The victor barely secured the verdict with judges scorecards of even score, narrow lead and 115-112, but each competitor were persistent and brave, exactly what their hero Hatton stood for.
