UK light-heavyweight Buatsi secured a victory yet unimpressive debut to life under recent management 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 10-round contest at the boxing arena.
But the challenger had his moments, landing some telling single shots in a fight where the techniques failed to mesh, with frequent clinching spoiling the action.
The scoring judges judged it 96-94 in favor to the winner, with the final judge a 95-95.
"It wasn't my greatest performance but how do champions respond? They succeed," Buatsi stated in the ringside as he was met by boos from the spectators.
The British fighter returned to winning ways after his first professional defeat - an memorable fight with Callum Smith in February - to secure a twentieth professional win.
Some ringside observers felt the challenger, thirty-one, should have been awarded the decision but the contender suffered the second defeat of his 28-bout professional journey.
The Champion Secures Triumph in Uneventful Encounter
His career development has slowed in recent times through management issues and long spells of inactivity.
Previously predicted as the rising talent of UK boxing, he now is positioned trying to fulfil that early promise - maybe in what appears to be a final roll of the dice - under fresh management.
He began cautiously, with both competitors willing to be aggressive in a cagey initial rounds.
Parker, whose single earlier setback came at super-middleweight against his former opponent in 2022 after breaking his hand in the contest, was competing in only his second bout at light heavyweight.
By the halfway stage, Parker had stayed in contention, making life awkward for Buatsi, who operated with a solid defense to barely take the better stanzas.
The spectators' acceptance wore thin amid regular grabbing, with the challenger falling to the floor various instances during grappling.
Parker ended stronger, but many rounds were hard to judge. However, former world champion Carl Frampton - working with the broadcast network - had it significantly in favor for Parker, scoring for Buatsi just only one stanza.
Buatsi advances, but with the likes of heavy hitter David Benavidez, and Russian champion Bivol leading the category, the journey to titles - on this evidence - still looks steep.
Ricky Hatton Tribute Motivates Manchester Derby Fight
In the supporting bout, Lyndon Arthur defeated Bradley Rea by split-decision in a excellent all-Manchester contest to win the European light heavyweight title.
The stadium grew hushed for a profoundly moving homage prior to the bout as ten bells sounded in remembrance of the city's native Ricky Hatton, who died aged 46 in September.
It was the initial significant broadcast fight night in the city since the passing of Hatton. As the concluding sound faded, the stillness became a roar of "there's only one Hatton".
The fighting during the bout equaled the sentiment. The eventual winner was floored by a powerful punch squarely on the chin in the initial stage, getting up unsteadily to his footing on the count of eight.
But the traditional red equipment of Arthur soon came forward again. Across the ring, Rea - in opposing blue - was marked up soon, noticeable damage forming under his face as the fighters exchanged powerful shots.
The challenger, 27, connected with strong blows but the champion, 34, matched the intensity with powerful upward punches as the action hardly diminished over 12 rounds.
Arthur narrowly won the decision with scoring tallies of draw, narrow lead and 115-112, but each competitor were persistent and courageous, exactly what their hero Hatton represented.
