UK light heavyweight Buatsi secured a victory yet underwhelming beginning to his career under recent management with a points victory over Zach Parker in the Manchester arena.
The Olympic bronze medallist's activity level seemingly secured him a majority decision in a competitive 10-round bout at the boxing arena.
But Parker had his moments, landing some telling individual punches in a match where the styles didn't complement each other, with frequent clinching marring the action.
Two judges had it 96-94 in favor to the winner, with the third a even score.
"It wasn't my best showing but how do champions respond? They succeed," Buatsi stated in the arena as he was greeted with disapproval from the audience.
The British fighter returned to winning ways after his initial pro loss - an thrilling contest with Callum Smith in February - to earn a twentieth professional win.
Some ringside observers thought Parker, thirty-one, merited the decision but the British boxer endured the second loss of his 28-bout professional journey.
The Champion Claims Win in Uneventful Encounter
Buatsi's progress has stalled in the past few years through promotional disputes and considerable time of lack of fights.
Once tipped as the next star of British boxing, he now is positioned trying to achieve expectations - possibly in what appears to be a final roll of the dice - under recent support.
He began cautiously, with both competitors prepared to be aggressive in a calculated initial rounds.
The challenger, whose single earlier setback came at super middleweight against his former opponent in 2022 after damaging his hand mid-fight, was making just his second appearance at the higher weight class.
By the halfway stage, the underdog had made it competitive, making life awkward for the favorite, who utilized a protective stance to edge the cleaner stanzas.
The spectators' acceptance decreased during constant clinching, with the challenger slipping to the canvas several times during clinches.
The underdog closed well, but several stanzas were hard to judge. However, former world champion the boxing analyst - working with Dazn - had it strongly leaning for Parker, scoring for Buatsi just a single round.
The victor advances, but with the likes of power puncher Benavidez, and Russian champion Dmitry Bivol leading the category, the path to championship success - on this evidence - still looks steep.
Ricky Hatton Tribute Inspires Manchester Derby Fight
In the secondary fight, Lyndon Arthur overcame Rea by divided decision in a outstanding local rivalry contest to win the European light-heavyweight title.
The stadium fell silent for a extremely emotional tribute ahead of the contest as 10 bells sounded in memory of Manchester's own Ricky Hatton, who passed away 46 years old in last month.
It was the premier televised match card in the location since the passing of Hatton. As the final chime disappeared, the stillness became a chant of "only one Ricky Hatton".
The action during the bout equaled the sentiment. Arthur was knocked down by a significant blow squarely on the chin in the initial stage, standing uncertainly to his position on the referee's count.
But the Manchester United-red attire of Arthur soon advanced again. On the opposite side, the opponent - in rival City blue - was damaged quickly, heavy swelling appearing under his eye as the pair landed hard punches.
The challenger, twenty-seven, delivered effective strikes but Arthur, thirty-four, responded in kind with powerful upward punches as the action seldom decreased over twelve rounds.
Arthur edged the verdict with official scores of draw, 115-113 and clearer margin, but each competitor were persistent and full of heart, all the qualities their hero Hatton represented.
