British light heavyweight Buatsi earned a win yet underwhelming debut to his career under fresh promotional backing with a points victory over Zach Parker in the Manchester arena.
The Olympic medal winner's work rate likely gained him a judges' verdict in a close ten-round contest at the boxing arena.
But Parker landed significant shots, landing some telling clean blows in a match where the approaches failed to mesh, with excessive holding marring the action.
Two judges scored it 96-94 for to the winner, with the final judge a 95-95 draw.
"It wasn't my finest performance but what do champions do? They prevail," the victor said in the arena as he was met by disapproval from the crowd.
The British fighter returned to winning ways after his first professional defeat - an memorable fight with his previous opponent in February - to claim a twentieth professional win.
Several boxing experts thought the challenger, thirty-one, should have been awarded the victory but the contender experienced the second setback of his 28-bout professional journey.
The Champion Claims Victory in Uneventful Encounter
Buatsi's progress has slowed in recent times through promotional disputes and considerable time of inactivity.
Earlier forecast as the future of the British fight scene, he now stands trying to achieve expectations - maybe in what seems like a last chance - under new promotional backing.
He started carefully, with the two boxers willing to be aggressive in a tentative initial rounds.
The challenger, whose only previous defeat came at super middleweight against his former opponent in two years ago after breaking his hand mid-fight, was participating in his second bout at light-heavyweight.
By the middle rounds, Parker had kept it close, making life awkward for the favorite, who operated with a solid defense to barely take the cleaner periods.
The audience's tolerance wore thin amid constant clinching, with Parker going down multiple occasions during clinches.
Parker closed well, but multiple periods were challenging to assess. Although, ex-champion the boxing analyst - providing analysis for Dazn - had it particularly wide for Parker, awarding Buatsi just only one stanza.
Buatsi moves on, but with the presence of heavy hitter David Benavidez, and Eastern European fighter Bivol leading the category, the path to championship success - based on this performance - still looks steep.
Hatton Homage Motivates All-Manchester Battle
In the supporting bout, Arthur beat Bradley Rea by split-decision in a outstanding local rivalry contest to win the continental belt.
The stadium grew hushed for a deeply poignant tribute prior to the bout as a bell ceremony rang in memory of local hero Ricky Hatton, who passed away aged 46 in September.
It was the first major televised fight night in the location since the passing of Hatton. As the last bell ended, the silence transitioned to a roar of "there's only one Hatton".
The competition within the ring equaled the feeling. Arthur was sent to the canvas by a significant blow flush on the chin in the second round, rising shakily to his position on the count of eight.
But the traditional red equipment of Arthur soon came forward again. Across the ring, Rea - in competitive blue - was injured quickly, significant bruising forming under his face as the duo exchanged powerful shots.
Rea, twenty-seven, landed power punches but the champion, thirty-four, responded in kind with stinging uppercuts as the pace rarely dropped over 12 rounds.
The victor edged the decision with judges scorecards of draw, 115-113 and clearer margin, but each competitor were persistent and courageous, exactly what their idol Hatton stood for.
