UK light heavyweight Buatsi made a winning yet disappointing debut to life under new promoters with a points victory over Zach Parker in the Manchester arena.
The Olympic bronze medallist's activity level appeared to earn him a split decision in a competitive ten-round fight at the Manchester venue.
But Parker had his moments, landing some telling clean blows in a contest where the techniques failed to mesh, with frequent clinching spoiling the contest.
Two judges scored it 96-94 for to Buatsi, with the final judge a even score.
"It wasn't my best showing but what do champions do? They prevail," the victor stated in the ringside as he was met by disapproval from the spectators.
The British fighter got back to winning after his maiden career setback - an epic battle with Callum Smith in last winter - to claim a twentieth professional win.
Various analysts thought Parker, 31, should have been awarded the win but the Derbyshire fighter experienced the second setback of his 28-fight professional journey.
Buatsi Secures Win in Slow Match
Buatsi's progress has stalled in recent times through promotional disputes and extended periods of inactivity.
Previously predicted as the future of the British fight scene, he now is positioned trying to achieve expectations - maybe in what feels like a ultimate opportunity - under new promotional backing.
He opened tentatively, with neither fighter ready to be aggressive in a cagey early stages.
Parker, whose sole prior loss came at super middleweight against John Ryder in two years ago after damaging his hand during the bout, was competing in only his second bout at light-heavyweight.
By the fight's midpoint, Parker had kept it close, causing problems for the favorite, who worked behind a solid defense to edge the more effective periods.
The spectators' acceptance diminished because of frequent holding, with the challenger slipping to the canvas several times during close exchanges.
Parker finished the stronger, but multiple periods were hard to judge. Nevertheless, previous titleholder the boxing analyst - working with the broadcast network - had it particularly wide for Parker, giving Buatsi just one round.
The victor advances, but with the caliber of heavy hitter David Benavidez, and Russian champion Bivol leading the category, the path to championship success - based on this performance - still seems difficult.
Hatton Memorial Motivates Manchester Derby Contest
In the co-main event, Arthur beat Bradley Rea by close verdict in a terrific local rivalry battle to secure the European light heavyweight championship.
The venue grew hushed for a profoundly moving homage ahead of the contest as ten bells rang in honor of the city's native Ricky Hatton, who passed away 46 years old in last month.
It was the first major televised fight night in the city since the passing of Hatton. As the concluding sound ended, the silence gave way to a chant of "there's just one Ricky Hatton".
The action during the bout matched the emotion. Arthur was floored by a significant blow flush on the chin in the initial stage, getting up unsteadily to his position on the count of eight.
But the Manchester United-red equipment of Arthur soon came forward again. From the other corner, the opponent - in competitive blue - was damaged early, significant bruising appearing under his orbital area as the fighters traded hard punches.
Rea, twenty-seven, delivered effective strikes but Arthur, thirty-four, matched the intensity with effective uppercuts as the pace seldom decreased over the full distance.
Arthur edged the verdict with judges scorecards of even score, 115-113 and 115-112, but both fighters were persistent and full of heart, all the qualities their hero Hatton represented.
