UK light heavyweight Buatsi made a winning yet disappointing beginning to life under recent management with a decision win over Zach Parker in Manchester.
The Olympic medal winner's work rate seemingly secured him a split decision in a close ten-round contest at the Co-op Live Arena.
But Parker had his moments, delivering effective individual punches in a contest where the techniques didn't complement each other, with frequent clinching disrupting the contest.
Two judges had it 96-94 in favor to Buatsi, with the third a 95-95.
"It wasn't my finest performance but what defines champions? They prevail," Buatsi said in the arena as he was met by boos from the spectators.
The Londoner got back to winning after his maiden career setback - an epic battle with his previous opponent in last winter - to secure a 20th pro success.
Various analysts felt the challenger, thirty-one, deserved the decision but the British boxer suffered the second defeat of his 28-bout professional journey.
The Champion Secures Triumph in Dull Encounter
His career development has stalled in the past few years through promotional disputes and considerable time of lack of fights.
Once tipped as the future of the British fight scene, he now finds himself trying to realize his potential - possibly in what seems like a ultimate opportunity - under fresh management.
He opened tentatively, with both competitors willing to be aggressive in a cagey initial rounds.
The challenger, whose only previous defeat came at super-middleweight against his former opponent in 2022 after breaking his hand during the bout, was participating in his second bout at the higher weight class.
By the halfway stage, the underdog had made it competitive, creating difficulties for Buatsi, who utilized a solid defense to barely take the more effective periods.
The crowd's patience diminished amid frequent holding, with the challenger going down several times during grappling.
The underdog closed well, but multiple periods were challenging to assess. Although, former world champion the boxing analyst - providing analysis for the broadcast network - had it particularly wide for the challenger, giving Buatsi just one round.
The victor advances, but with the likes of heavy hitter Benavidez, and Russian star Bivol leading the category, the road to world glory - judging by this showing - still seems difficult.
Ricky Hatton Memorial Inspires All-Manchester Contest
In the co-main event, Lyndon Arthur overcame Bradley Rea by close verdict in a excellent Manchester vs Manchester battle to capture the European light heavyweight belt.
The stadium fell silent for a deeply poignant memorial before the fight as 10 bells tolled in remembrance of local hero Hatton, who passed away 46 years old in last month.
It was the premier televised boxing event in the urban center since the passing of Hatton. As the concluding sound disappeared, the stillness gave way to a roar of "only one Hatton".
The fighting during the bout equaled the sentiment. Arthur was knocked down by a powerful punch directly to the chin in the second round, standing uncertainly to his feet on the eight count.
But the traditional red shorts of the fighter soon came forward again. On the opposite side, the opponent - in opposing blue - was injured quickly, significant bruising forming under his orbital area as the duo traded punishing blows.
The challenger, 27, delivered effective strikes but Arthur, 34, responded in kind with effective uppercuts as the action seldom decreased over 12 rounds.
Arthur narrowly won the verdict with scoring tallies of 114-114, narrow lead and clearer margin, but each competitor were relentless and full of heart, exactly what their idol the legend stood for.
