UK light heavyweight Buatsi earned a win yet underwhelming debut to his career under fresh promotional backing with a points victory over Zach Parker in Manchester.
The Olympic medal winner's punch output seemingly secured him a split decision in a competitive 10-round fight at the boxing arena.
But the challenger had his moments, connecting with powerful clean blows in a match where the styles never quite clicked, with frequent clinching marring the contest.
The scoring judges had it 96-94 for to Buatsi, with the final judge a 95-95.
"It wasn't my finest showing but what do champions do? They win," Buatsi stated in the ring as he was met by boos from the spectators.
The British fighter returned to winning ways after his first professional defeat - an epic battle with Callum Smith in last winter - to earn a 20th career victory.
Some ringside observers felt Parker, 31, merited the win but the contender endured the second defeat of his 28-fight professional journey.
Buatsi Secures Win in Slow Affair
His career development has slowed in recent years through management issues and considerable time of lack of fights.
Previously predicted as the future of British boxing, he now is positioned trying to fulfil that early promise - maybe in what feels like a ultimate opportunity - under fresh management.
He opened tentatively, with neither fighter prepared to take risks in a tentative opening few rounds.
The challenger, whose sole prior loss came at super middleweight against his former opponent in 2022 after breaking his hand in the contest, was competing in only his second appearance at light heavyweight.
By the middle rounds, the underdog had stayed in contention, causing problems for the favorite, who operated with a solid defense to barely take the better rounds.
The audience's tolerance decreased amid regular grabbing, with Parker slipping to the canvas various instances during grappling.
Parker closed well, but multiple periods were difficult to score. Although, previous titleholder the boxing analyst - providing analysis for the broadcast network - had it particularly wide for Parker, awarding Buatsi just a single round.
The victor advances, but with the likes of power puncher David Benavidez, and Eastern European fighter Bivol dominating the weight class, the road to world glory - based on this performance - still appears challenging.
Hatton Memorial Fuels Local Rivalry Fight
In the supporting bout, Arthur defeated Rea by split-decision in a excellent all-Manchester fight to secure the European light heavyweight title.
The arena grew hushed for a deeply poignant memorial ahead of the contest as ten bells rang in memory of Manchester's own Ricky Hatton, who died 46 years old in recently.
It was the initial significant broadcast boxing event in the urban center since Hatton's passing. As the last bell disappeared, the silence gave way to a shout of "there's only one Ricky Hatton".
The fighting during the bout equaled the sentiment. The eventual winner was sent to the canvas by a left hook flush on the face in the early round, rising shakily to his feet on the count of eight.
But the Manchester United-red attire of the fighter soon advanced again. Across the ring, the opponent - in opposing blue - was damaged quickly, noticeable damage developing under his eye as the fighters traded hard punches.
The challenger, 27, landed power punches but Arthur, 34, fought fire with fire with powerful upward punches as the pace hardly diminished over 12 rounds.
Arthur barely secured the decision with judges scorecards of even score, close margin and clearer margin, but the two athletes were relentless and full of heart, everything their idol Hatton embodied.
