British light-heavyweight Buatsi earned a win yet underwhelming start to life under recent management with a points victory over Zach Parker in Manchester.
The Olympic bronze medallist's punch output appeared to earn him a majority decision in a competitive ten-round fight at the boxing arena.
But Parker landed significant shots, delivering effective single shots in a contest where the styles failed to mesh, with excessive holding spoiling the fight.
Two judges scored it 96-94 for to Buatsi, with the final judge a 95-95 draw.
"It wasn't my greatest performance but what do champions do? They succeed," Buatsi commented in the ringside as he was met by disapproval from the crowd.
The British fighter got back to winning after his maiden career setback - an epic battle with Callum Smith in February - to earn a twentieth professional win.
Several boxing experts thought Parker, 31, merited the decision but the contender experienced the second defeat of his 28-bout career.
Buatsi Earns Win in Slow Affair
The fighter's advancement has stalled in the past few years through promotional disputes and extended periods of lack of fights.
Earlier forecast as the next star of British boxing, he now finds himself trying to fulfil that early promise - maybe in what seems like a last chance - under new promotional backing.
He started carefully, with neither fighter prepared to be aggressive in a cagey early stages.
Parker, whose only previous defeat came at super-middleweight against his former opponent in two years ago after suffering a hand injury mid-fight, was participating in his second fight at the higher weight class.
By the halfway stage, Parker had stayed in contention, causing problems for Buatsi, who worked behind a solid defense to narrowly win the better periods.
The crowd's patience wore thin because of constant clinching, with Parker falling to the floor various instances during grappling.
Parker ended stronger, but multiple periods were difficult to score. Although, previous titleholder the boxing analyst - working with Dazn - had it significantly in favor for the challenger, scoring for Buatsi just only one stanza.
The victor progresses, but with the caliber of heavy hitter Benavidez, and Russian star Bivol dominating the weight class, the journey to titles - judging by this showing - still seems difficult.
Ricky Hatton Homage Fuels Local Rivalry Contest
In the co-main event, Arthur defeated Rea by close verdict in a terrific all-Manchester contest to win the continental belt.
The arena fell silent for a profoundly moving homage prior to the bout as a bell ceremony rang in remembrance of Manchester's own Ricky Hatton, who passed away at age 46 in September.
It was the premier televised match card in the urban center since Hatton's passing. As the final chime ended, the quiet transitioned to a chant of "only one Ricky Hatton".
The fighting inside the ropes matched the sentiment. The eventual winner was sent to the canvas by a significant blow directly to the face in the early round, getting up unsteadily to his position on the count of eight.
But the red-colored shorts of the fighter soon came forward again. On the opposite side, Rea - in rival City blue - was marked up quickly, heavy swelling developing under his face as the fighters exchanged hard punches.
The challenger, twenty-seven, landed power punches but Arthur, thirty-four, matched the intensity with effective uppercuts as the intensity seldom decreased over the full distance.
Arthur edged the verdict with official scores of draw, close margin and 115-112, but each competitor were determined and full of heart, all the qualities their inspiration the legend embodied.
