British light-heavyweight Buatsi made a winning yet unimpressive debut to life under new promoters with a decision win over Zach Parker in Manchester.
The Olympic bronze medallist's punch output seemingly secured him a judges' verdict in a close ten-round fight at the Co-op Live Arena.
But the challenger found success, landing some telling single shots in a contest where the techniques didn't complement each other, with constant grabbing disrupting the action.
The scoring judges scored it 96-94 in favor to the winner, with the remaining official a 95-95 draw.
"It wasn't my finest display but what defines champions? They succeed," Buatsi commented in the ringside as he was greeted with negative reactions from the crowd.
The British fighter returned to winning ways after his first professional defeat - an thrilling contest with Callum Smith in last winter - to secure a 20th pro success.
Some ringside observers felt Parker, thirty-one, deserved the victory but the Derbyshire fighter endured the second loss of his 28-match career.
Buatsi Secures Victory in Dull Encounter
The fighter's advancement has stalled in recent years through promotional disputes and extended periods of inactivity.
Previously predicted as the future of UK boxing, he now is positioned trying to fulfil that early promise - perhaps in what appears to be a final roll of the dice - under new promotional backing.
He opened tentatively, with neither fighter willing to overcommit in a calculated opening few rounds.
Parker, whose single earlier setback came at the lower weight class against his former opponent in 2022 after breaking his hand mid-fight, was participating in his second fight at the higher weight class.
By the middle rounds, Parker had stayed in contention, making life awkward for Buatsi, who worked behind a tight guard to barely take the cleaner periods.
The crowd's patience decreased because of constant clinching, with the challenger falling to the floor several times during grappling.
Parker ended stronger, but many rounds were difficult to score. However, ex-champion Carl Frampton - providing analysis for Dazn - had it particularly wide for Parker, scoring for Buatsi just a single round.
The victor advances, but with the likes of hard hitter David Benavidez, and Russian star Dmitry Bivol leading the category, the road to world glory - on this evidence - still appears challenging.
Ricky Hatton Tribute Inspires Local Rivalry Contest
In the co-main event, Arthur overcame Bradley Rea by split-decision in a terrific all-Manchester fight to secure the European light heavyweight championship.
The arena fell silent for a profoundly moving tribute before the fight as a bell ceremony tolled in memory of the city's native Hatton, who succumbed aged 46 in last month.
It was the premier televised fight night in the location since Hatton's death. As the final chime disappeared, the silence transitioned to a chant of "there's only one Ricky Hatton".
The fighting within the ring reflected the sentiment. Arthur was knocked down by a left hook flush on the jaw in the second round, getting up unsteadily to his footing on the count of eight.
But the Manchester United-red attire of Arthur soon pressed ahead again. From the other corner, the opponent - in competitive blue - was injured early, heavy swelling developing under his face as the fighters landed punishing blows.
The challenger, twenty-seven, landed power punches but the champion, 34, responded in kind with effective uppercuts as the action rarely dropped over the full distance.
Arthur narrowly won the verdict with official scores of even score, 115-113 and 115-112, but both fighters were persistent and brave, exactly what their hero the legend represented.
