UK light heavyweight Buatsi made a winning yet unimpressive beginning to his career under recent management with a unanimous decision 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 single shots in a contest where the styles failed to mesh, with excessive holding disrupting the fight.
The officials had it 96-94 in favor to Buatsi, with the remaining official a 95-95 draw.
"It wasn't my finest display but how do champions respond? They succeed," Buatsi commented in the arena as he was greeted with boos from the spectators.
The British fighter returned to winning ways after his initial pro loss - an epic battle with his previous opponent in last winter - to secure a 20th pro success.
Several boxing experts believed the challenger, thirty-one, should have been awarded the decision but the contender endured the second loss of his 28-match career.
The Champion Claims Win in Dull Match
The fighter's advancement has stalled in recent times through promotional disputes and extended periods of lack of fights.
Once tipped as the next star of British boxing, he now finds himself trying to fulfil that early promise - perhaps in what feels like a final roll of the dice - under recent support.
He began cautiously, with the two boxers willing to take risks in a tentative initial rounds.
Parker, whose single earlier setback came at super middleweight against John Ryder in 2022 after breaking his hand in the contest, was participating in his second bout at light-heavyweight.
By the fight's midpoint, the underdog had made it competitive, creating difficulties for the favorite, who worked behind a tight guard to edge the better periods.
The spectators' acceptance diminished because of frequent holding, with Parker falling to the floor various instances during clinches.
The underdog finished the stronger, but several stanzas were hard to judge. However, previous titleholder the boxing analyst - commentating on Dazn - had it strongly leaning for the challenger, giving Buatsi just a single round.
Buatsi progresses, but with the presence of hard hitter David Benavidez, and Russian champion Dmitry Bivol leading the category, the road to world glory - on this evidence - still seems difficult.
Hatton Memorial Motivates All-Manchester Contest
In the co-main event, Lyndon Arthur overcame Rea by close verdict in a excellent local rivalry battle to win the continental belt.
The arena became quiet for a extremely emotional tribute ahead of the contest as 10 bells tolled in honor of Manchester's own Ricky Hatton, who succumbed aged 46 in recently.
It was the initial significant broadcast match card in the location since Hatton's passing. As the last bell disappeared, the stillness became a shout of "only one Ricky Hatton".
The action during the bout matched the feeling. Arthur was sent to the canvas by a significant blow squarely on the chin in the second round, standing uncertainly to his feet on the eight count.
But the Manchester United-red shorts of the fighter soon pressed ahead again. From the other corner, Rea - in rival City blue - was injured soon, noticeable damage developing under his face as the duo landed hard punches.
The challenger, twenty-seven, delivered effective strikes but Arthur, thirty-four, responded in kind with effective uppercuts as the intensity rarely dropped over twelve rounds.
The victor barely secured the result with official scores of 114-114, close margin and wider gap, but the two athletes were persistent and brave, all the qualities their inspiration Hatton stood for.
