UK light-heavyweight Buatsi made a winning yet unimpressive start to life under new promoters with a decision win over Zach Parker in the Manchester arena.
The Olympic bronze medallist's work rate likely gained him a judges' verdict in a close 10-round fight at the Manchester venue.
But Parker landed significant shots, landing some telling clean blows in a match where the techniques failed to mesh, with excessive holding spoiling the fight.
The scoring judges had it 96-94 in favor to Buatsi, with the remaining official a even score.
"It wasn't my finest display but what do champions do? They prevail," the victor said in the ringside as he was greeted with disapproval from the spectators.
The Londoner got back to winning after his maiden career setback - an thrilling contest with his previous opponent in last winter - to secure a twentieth professional win.
Various analysts believed Parker, 31, should have been awarded the victory but the Derbyshire fighter experienced the second loss of his 28-match career.
The Champion Secures Triumph in Uneventful Match
Buatsi's progress has stalled in recent times through management issues and considerable time of inactivity.
Earlier forecast as the next star of British boxing, he now finds himself trying to achieve expectations - possibly in what appears to be a ultimate opportunity - under recent support.
He started carefully, with neither fighter prepared to be aggressive in a cagey initial rounds.
Parker, whose sole prior loss came at the lower weight class against his former opponent in two years ago after breaking his hand mid-fight, was competing in only his second fight at the higher weight class.
By the fight's midpoint, the underdog had stayed in contention, making life awkward for the favorite, who worked behind a solid defense to barely take the better periods.
The crowd's patience diminished amid regular grabbing, with Parker slipping to the canvas multiple occasions during clinches.
Parker finished the stronger, but multiple periods were challenging to assess. However, ex-champion Carl Frampton - commentating on Dazn - had it significantly in favor for Parker, giving Buatsi just one round.
The victor advances, but with the likes of heavy hitter David Benavidez, and Eastern European fighter Bivol ruling the division, the journey to titles - judging by this showing - still appears challenging.
Hatton Tribute Fuels Manchester Derby Fight
In the secondary fight, Arthur defeated Rea by divided decision in a excellent local rivalry battle to capture the European light heavyweight championship.
The venue fell silent for a deeply poignant tribute ahead of the contest as a bell ceremony tolled in memory of Manchester's own Hatton, who succumbed aged 46 in last month.
It was the initial significant broadcast match card in the location since Hatton's passing. As the last bell ended, the silence became a roar of "there's just one Ricky Hatton".
The fighting within the ring matched the sentiment. The eventual winner was floored by a significant blow directly to the chin in the early round, getting up unsteadily to his position on the referee's count.
But the red-colored shorts of the fighter soon pressed ahead again. Across the ring, Rea - in rival City blue - was injured early, noticeable damage developing under his eye as the fighters exchanged punishing blows.
Rea, twenty-seven, landed power punches but Arthur, 34, fought fire with fire with stinging uppercuts as the action seldom decreased over twelve rounds.
Arthur barely secured the result with judges scorecards of even score, narrow lead and wider gap, but the two athletes were determined and full of heart, all the qualities their idol the legend embodied.
