UK light heavyweight Buatsi earned a win yet underwhelming debut to life under new promoters with a points victory over Zach Parker in the Manchester arena.
The Olympic medal winner's activity level appeared to earn him a split decision in a tight 10-round fight at the Manchester venue.
But Parker found success, delivering effective single shots in a fight where the styles didn't complement each other, with excessive holding disrupting the fight.
The scoring judges judged it 96-94 for to Buatsi, with the third a 95-95 draw.
"It wasn't my finest display but how do champions respond? They succeed," the victor commented in the ring as he was faced negative reactions from the audience.
The British fighter got back to winning after his maiden career setback - an thrilling contest with Callum Smith in last winter - to earn a 20th pro success.
Some ringside observers felt the challenger, thirty-one, merited the decision but the Derbyshire fighter experienced the second setback of his 28-bout professional journey.
Buatsi Secures Triumph in Dull Match
The fighter's advancement has plateaued in recent times through promotional disputes and extended periods of lack of fights.
Previously predicted as the next star of British boxing, he now stands trying to fulfil that early promise - possibly in what seems like a ultimate opportunity - under new promotional backing.
He began cautiously, with both competitors prepared to take risks in a tentative early stages.
The challenger, whose only previous defeat came at super-middleweight against his former opponent in two years ago after breaking his hand during the bout, was making just his second bout at the higher weight class.
By the middle rounds, Parker had stayed in contention, making life awkward for Buatsi, who operated with a tight guard to barely take the more effective periods.
The crowd's patience diminished amid frequent holding, with Parker going down multiple occasions during clinches.
The underdog finished the stronger, but many rounds were difficult to score. Nevertheless, previous titleholder the boxing analyst - providing analysis for the broadcast network - had it strongly leaning for Parker, awarding Buatsi just only one stanza.
Buatsi advances, but with the presence of heavy hitter David Benavidez, and Eastern European fighter Dmitry Bivol leading the category, the road to world glory - based on this performance - still looks steep.
Hatton Memorial Fuels All-Manchester Contest
In the co-main event, Arthur defeated Bradley Rea by split-decision in a excellent all-Manchester contest to win the continental championship.
The stadium fell silent for a profoundly moving memorial ahead of the contest as ten bells sounded in memory of local hero Hatton, who passed away aged 46 in recently.
It was the first major televised fight night in the urban center since Hatton's death. As the final chime disappeared, the silence became a roar of "only one Hatton".
The action within the ring matched the sentiment. The eventual winner was sent to the canvas by a left hook directly to the jaw in the early round, getting up unsteadily to his feet on the count of eight.
But the traditional red shorts of Arthur soon advanced again. Across the ring, Rea - in rival City blue - was marked up quickly, heavy swelling forming under his face as the pair landed hard punches.
The challenger, twenty-seven, connected with strong blows but Arthur, 34, fought fire with fire with powerful upward punches as the intensity hardly diminished over 12 rounds.
The victor narrowly won the verdict with judges scorecards of even score, 115-113 and wider gap, but each competitor were relentless and full of heart, all the qualities their idol the legend stood for.
