British light heavyweight Buatsi earned a win yet disappointing start to his career under recent management with a decision win over Zach Parker in Manchester.
The Olympic bronze medallist's punch output likely gained him a judges' verdict in a close ten-round fight at the Co-op Live Arena.
But the challenger found success, delivering effective individual punches in a contest where the techniques failed to mesh, with excessive holding disrupting the contest.
The officials had it 96-94 for to Buatsi, with the final judge a 95-95.
"It wasn't my finest performance but what defines champions? They succeed," Buatsi commented in the ring as he was greeted with disapproval from the crowd.
The Londoner got back to winning after his maiden career setback - an memorable fight with Callum Smith in February - to claim a 20th pro success.
Various analysts believed the challenger, thirty-one, merited the victory but the contender experienced the second loss of his 28-bout professional journey.
Buatsi Secures Win in Slow Encounter
Buatsi's progress has slowed in recent times through contract problems and considerable time of inactivity.
Earlier forecast as the future of the British fight scene, he now finds himself trying to realize his potential - maybe in what seems like a final roll of the dice - under new promotional backing.
He began cautiously, with neither fighter ready to overcommit in a tentative early stages.
The challenger, whose single earlier setback came at the lower weight class against John Ryder in 2022 after breaking his hand during the bout, was participating in his second appearance at light-heavyweight.
By the halfway stage, the underdog had made it competitive, creating difficulties for Buatsi, who operated with a tight guard to narrowly win the more effective rounds.
The audience's tolerance diminished because of constant clinching, with Parker slipping to the canvas various instances during close exchanges.
Parker closed well, but many rounds were difficult to score. However, former world champion Carl Frampton - working with Dazn - had it significantly in favor for Parker, scoring for Buatsi just a single round.
Buatsi advances, but with the presence of hard hitter Benavidez, and Russian star Bivol leading the category, the path to championship success - based on this performance - still appears challenging.
Ricky Hatton Memorial Motivates All-Manchester Contest
In the secondary fight, Arthur beat Bradley Rea by close verdict in a terrific local rivalry battle to capture the European light-heavyweight belt.
The stadium became quiet for a deeply poignant memorial prior to the bout as a bell ceremony rang in memory of the city's native Ricky Hatton, who died aged 46 in recently.
It was the first major televised match card in the urban center since Hatton's death. As the concluding sound ended, the quiet transitioned to a roar of "there's only one Hatton".
The action inside the ropes reflected the emotion. The eventual winner was knocked down by a powerful punch squarely on the chin in the early round, getting up unsteadily to his feet on the referee's count.
But the Manchester United-red equipment of Arthur soon pressed ahead again. On the opposite side, the opponent - in opposing blue - was marked up early, heavy swelling appearing under his eye as the pair traded hard punches.
The challenger, 27, landed power punches but the champion, 34, responded in kind with powerful upward punches as the action seldom decreased over twelve rounds.
The victor edged the decision with judges scorecards of 114-114, close margin and clearer margin, but each competitor were relentless and full of heart, everything their hero the legend stood for.
