UK light-heavyweight Buatsi secured a victory yet disappointing start to life under recent management with a decision win over Zach Parker in the Manchester arena.
The Olympic medal winner's activity level seemingly secured him a majority decision in a tight ten-round fight at the boxing arena.
But the challenger had his moments, delivering effective clean blows in a fight where the techniques failed to mesh, with excessive holding marring the action.
Two judges had it 96-94 in favor to Buatsi, with the remaining official a 95-95 draw.
"It wasn't my best display but what defines champions? They win," the victor stated in the arena as he was faced boos from the crowd.
The Londoner bounced back after his first professional defeat - an thrilling contest with his previous opponent in February - to claim a twentieth professional win.
Several boxing experts felt the challenger, 31, should have been awarded the decision but the British boxer suffered the second loss of his 28-fight professional journey.
The Champion Claims Win in Slow Affair
The fighter's advancement has slowed in the past few years through management issues and considerable time of inactivity.
Previously predicted as the future of UK boxing, he now stands trying to realize his potential - possibly in what appears to be a final roll of the dice - under new promotional backing.
He opened tentatively, with both competitors ready to take risks in a cagey early stages.
Parker, whose only previous defeat came at super middleweight against John Ryder in two years ago after breaking his hand in the contest, was participating in his second fight at the higher weight class.
By the halfway stage, Parker had stayed in contention, creating difficulties for Buatsi, who worked behind a tight guard to barely take the cleaner periods.
The crowd's patience diminished amid regular grabbing, with Parker falling to the floor several times during clinches.
Parker ended stronger, but many rounds were difficult to score. Nevertheless, ex-champion Carl Frampton - working with the broadcast network - had it significantly in favor for Parker, giving Buatsi just one round.
The victor moves on, but with the likes of hard hitter David Benavidez, and Eastern European fighter Dmitry Bivol leading the category, the path to championship success - judging by this showing - still looks steep.
Ricky Hatton Tribute Motivates All-Manchester Contest
In the co-main event, Arthur defeated Bradley Rea by divided decision in a terrific all-Manchester battle to capture the European light-heavyweight championship.
The arena became quiet for a deeply poignant homage before the fight as 10 bells sounded in remembrance of the city's native Hatton, who died aged 46 in September.
It was the first major televised boxing event in the city since Hatton's death. As the final chime faded, the stillness transitioned to a roar of "there's just one Hatton".
The action within the ring reflected the emotion. The eventual winner was knocked down by a powerful punch squarely on the chin in the second round, standing uncertainly to his feet on the referee's count.
But the Manchester United-red shorts of Arthur soon advanced again. On the opposite side, Rea - in opposing blue - was injured quickly, heavy swelling developing under his eye as the fighters exchanged powerful shots.
The challenger, 27, connected with strong blows but the champion, thirty-four, fought fire with fire with powerful upward punches as the action seldom decreased over 12 rounds.
Arthur narrowly won the decision with official scores of 114-114, 115-113 and 115-112, but both fighters were persistent and courageous, exactly what their idol Hatton represented.
