UK light-heavyweight Buatsi made a winning yet unimpressive beginning to his career under recent management with a points victory over Zach Parker in the Manchester arena.
The Olympic medal winner's work rate seemingly secured him a majority decision in a competitive 10-round bout at the Manchester venue.
But the challenger had his moments, delivering effective individual punches in a fight where the styles failed to mesh, with frequent clinching disrupting the fight.
The scoring judges scored it 96-94 in favor to Buatsi, with the remaining official a even score.
"It wasn't my best showing but what defines champions? They succeed," Buatsi commented in the ring as he was met by negative reactions from the spectators.
The British fighter bounced back after his first professional defeat - an memorable fight with Callum Smith in February - to earn a 20th pro success.
Various analysts believed the challenger, thirty-one, merited the win but the contender endured the second defeat of his 28-match professional journey.
Buatsi Claims Win in Slow Match
The fighter's advancement has plateaued in recent years through management issues and extended periods of inactivity.
Earlier forecast as the next star of UK boxing, he now finds himself trying to realize his potential - perhaps in what feels like a ultimate opportunity - under new promotional backing.
He began cautiously, with both competitors ready to be aggressive in a calculated early stages.
Parker, whose sole prior loss came at super middleweight against John Ryder in two years ago after suffering a hand injury mid-fight, was competing in only his second appearance at the higher weight class.
By the fight's midpoint, the underdog had stayed in contention, making life awkward for Buatsi, who operated with a solid defense to barely take the more effective stanzas.
The crowd's patience wore thin amid regular grabbing, with Parker falling to the floor multiple occasions during close exchanges.
The underdog closed well, but many rounds were hard to judge. Nevertheless, ex-champion Carl Frampton - providing analysis for the broadcast network - had it particularly wide for Parker, giving Buatsi just one round.
Buatsi advances, but with the caliber of heavy hitter David Benavidez, and Russian star Bivol dominating the weight class, the road to world glory - based on this performance - still appears challenging.
Ricky Hatton Memorial Inspires All-Manchester Contest
In the secondary fight, Lyndon Arthur defeated Bradley Rea by divided decision in a excellent local rivalry battle to win the European light heavyweight belt.
The stadium fell silent for a deeply poignant tribute ahead of the contest as a bell ceremony rang in honor of local hero Ricky Hatton, who succumbed aged 46 in September.
It was the premier televised fight night in the urban center since Hatton's death. As the concluding sound ended, the stillness became a shout of "there's just one Ricky Hatton".
The fighting within the ring reflected the emotion. Arthur was sent to the canvas by a powerful punch flush on the jaw in the second round, standing uncertainly to his feet on the eight count.
But the red-colored equipment of the fighter soon advanced again. On the opposite side, the opponent - in competitive blue - was marked up early, heavy swelling developing under his eye as the pair exchanged punishing blows.
Rea, 27, delivered effective strikes but the champion, thirty-four, responded in kind with stinging uppercuts as the intensity seldom decreased over twelve rounds.
Arthur edged the decision with official scores of draw, 115-113 and clearer margin, but both fighters were determined and full of heart, everything their inspiration the legend stood for.
