British light-heavyweight Buatsi secured a victory yet underwhelming beginning to his career under new promoters with a points victory over Zach Parker in the Manchester arena.
The Olympic bronze medallist's work rate likely gained him a majority decision in a close ten-round fight at the Manchester venue.
But Parker found success, delivering effective single shots in a contest where the approaches failed to mesh, with frequent clinching spoiling the action.
The officials judged it 96-94 in favor to Buatsi, with the final judge a 95-95 draw.
"It wasn't my finest showing but how do champions respond? They prevail," the victor commented in the ringside as he was greeted with boos from the audience.
The British fighter got back to winning after his maiden career setback - an thrilling contest with his previous opponent in last winter - to claim a twentieth professional win.
Several boxing experts thought Parker, thirty-one, should have been awarded the decision but the Derbyshire fighter endured the second defeat of his 28-match career.
Buatsi Secures Win in Uneventful Encounter
Buatsi's progress has slowed in recent years through management issues and extended periods of lack of fights.
Once tipped as the rising talent of British boxing, he now is positioned trying to fulfil that early promise - maybe in what appears to be a final roll of the dice - under recent support.
He began cautiously, with both competitors prepared to be aggressive in a tentative opening few rounds.
The challenger, whose sole prior loss came at the lower weight class against John Ryder in 2022 after damaging his hand in the contest, was competing in only his second fight at light-heavyweight.
By the fight's midpoint, the underdog had kept it close, creating difficulties for Buatsi, who worked behind a tight guard to narrowly win the better periods.
The audience's tolerance decreased amid frequent holding, with Parker slipping to the canvas several times during grappling.
Parker ended stronger, but multiple periods were hard to judge. Nevertheless, ex-champion the boxing analyst - commentating on the broadcast network - had it significantly in favor for Parker, scoring for Buatsi just one round.
The victor advances, but with the likes of power puncher Benavidez, and Russian champion Dmitry Bivol dominating the weight class, the path to championship success - judging by this showing - still looks steep.
Ricky Hatton Memorial Motivates Local Rivalry Contest
In the supporting bout, Arthur beat Bradley Rea by split-decision in a terrific Manchester vs Manchester battle to secure the European light-heavyweight title.
The venue grew hushed for a deeply poignant memorial prior to the bout as a bell ceremony sounded in remembrance of the city's native Ricky Hatton, who died aged 46 in September.
It was the first major televised match card in the urban center since Hatton's passing. As the final chime disappeared, the stillness transitioned to a roar of "there's just one Ricky Hatton".
The competition during the bout reflected the emotion. Arthur was sent to the canvas by a significant blow squarely on the face in the early round, getting up unsteadily to his position on the eight count.
But the Manchester United-red shorts of Arthur soon came forward again. On the opposite side, the opponent - in rival City blue - was injured early, noticeable damage forming under his eye as the fighters landed powerful shots.
Rea, twenty-seven, landed power punches but the champion, 34, matched the intensity with effective uppercuts as the pace rarely dropped over the full distance.
Arthur barely secured the verdict with scoring tallies of even score, narrow lead and 115-112, but the two athletes were determined and brave, everything their inspiration Hatton stood for.
