UK light-heavyweight Buatsi made a winning yet underwhelming beginning to his career under fresh promotional backing with a unanimous decision over Zach Parker in Manchester.
The Olympic medal winner's activity level appeared to earn him a judges' verdict in a close 10-round bout at the Manchester venue.
But the challenger landed significant shots, landing some telling clean blows in a contest where the styles didn't complement each other, with constant grabbing spoiling the contest.
The officials judged it 96-94 for to Buatsi, with the final judge a even score.
"It wasn't my greatest performance but what do champions do? They win," the victor said in the arena as he was faced disapproval from the crowd.
The British fighter returned to winning ways after his maiden career setback - an memorable fight with his previous opponent in last winter - to claim a twentieth professional win.
Some ringside observers felt Parker, 31, merited the decision but the British boxer endured the second loss of his 28-match professional journey.
Buatsi Secures Win in Slow Affair
Buatsi's progress has stalled in recent years through management issues and considerable time of inactivity.
Once tipped as the next star of UK boxing, he now is positioned trying to fulfil that early promise - perhaps in what seems like a ultimate opportunity - under recent support.
He opened tentatively, with the two boxers prepared to overcommit in a cagey opening few rounds.
Parker, whose only previous defeat came at super-middleweight against his former opponent in two years ago after suffering a hand injury during the bout, was participating in his second bout at light heavyweight.
By the fight's midpoint, Parker had stayed in contention, creating difficulties for the favorite, who utilized a protective stance to narrowly win the cleaner rounds.
The crowd's patience diminished during constant clinching, with the challenger slipping to the canvas multiple occasions during close exchanges.
The underdog ended stronger, but many rounds were challenging to assess. Although, previous titleholder the boxing analyst - working with the broadcast network - had it particularly wide for the challenger, giving Buatsi just a single round.
The victor advances, but with the presence of hard hitter David Benavidez, and Eastern European fighter Dmitry Bivol ruling the division, the journey to titles - based on this performance - still seems difficult.
Ricky Hatton Tribute Inspires Local Rivalry Fight
In the secondary fight, Arthur overcame Bradley Rea by split-decision in a outstanding all-Manchester battle to win the European light heavyweight title.
The venue fell silent for a profoundly moving homage before the fight as a bell ceremony rang in remembrance of the city's native Ricky Hatton, who died 46 years old in last month.
It was the premier televised fight night in the city since Hatton's death. As the last bell disappeared, the stillness transitioned to a roar of "there's only one Ricky Hatton".
The fighting during the bout equaled the sentiment. Arthur was floored by a significant blow directly to the face in the second round, getting up unsteadily to his position on the eight count.
But the red-colored equipment of Arthur soon pressed ahead again. On the opposite side, the opponent - in rival City blue - was marked up quickly, heavy swelling appearing under his face as the fighters traded punishing blows.
Rea, 27, landed power punches but Arthur, thirty-four, matched the intensity with stinging uppercuts as the pace hardly diminished over 12 rounds.
Arthur edged the result with official scores of 114-114, 115-113 and clearer margin, but both fighters were determined and brave, everything their hero the legend represented.
