British light-heavyweight Buatsi secured a victory yet unimpressive beginning to life under fresh promotional backing with a decision win over Zach Parker in the Manchester arena.
The Olympic bronze medallist's work rate likely gained him a split decision in a tight 10-round fight at the boxing arena.
But Parker landed significant shots, connecting with powerful single shots in a contest where the techniques failed to mesh, with constant grabbing marring the contest.
The officials had it 96-94 for to the winner, with the final judge a 95-95 draw.
"It wasn't my finest performance but what do champions do? They win," Buatsi stated in the ring as he was met by boos from the audience.
The Londoner bounced back after his maiden career setback - an epic battle with his previous opponent in February - to claim a twentieth professional win.
Several boxing experts felt Parker, thirty-one, deserved the win but the contender endured the second setback of his 28-fight professional journey.
Buatsi Secures Victory in Uneventful Match
Buatsi's progress has slowed in recent years through contract problems and extended periods of lack of fights.
Previously predicted as the rising talent of the British fight scene, he now is positioned trying to achieve expectations - perhaps in what feels like a last chance - under recent support.
He began cautiously, with the two boxers prepared to be aggressive in a cagey early stages.
Parker, whose single earlier setback came at super-middleweight against John Ryder in two years ago after damaging his hand mid-fight, was competing in only his second fight at light heavyweight.
By the halfway stage, Parker had stayed in contention, creating difficulties for Buatsi, who operated with a protective stance to narrowly win the better rounds.
The crowd's patience decreased amid constant clinching, with the challenger slipping to the canvas several times during clinches.
Parker closed well, but many rounds were hard to judge. Although, former world champion the boxing analyst - commentating on the broadcast network - had it strongly leaning for the challenger, awarding Buatsi just one round.
Buatsi moves on, but with the likes of power puncher Benavidez, and Russian star Dmitry Bivol leading the category, the path to championship success - on this evidence - still seems difficult.
Ricky Hatton Tribute Inspires Manchester Derby Fight
In the co-main event, Lyndon Arthur defeated Bradley Rea by divided decision in a terrific local rivalry battle to capture the continental title.
The stadium grew hushed for a profoundly moving homage ahead of the contest as ten bells tolled in remembrance of local hero Hatton, who passed away aged 46 in September.
It was the first major televised fight night in the city since the passing of Hatton. As the concluding sound ended, the stillness transitioned to a shout of "there's just one Hatton".
The fighting during the bout equaled the feeling. Arthur was knocked down by a significant blow directly to the face in the second round, standing uncertainly to his position on the count of eight.
But the red-colored equipment of Arthur soon pressed ahead again. Across the ring, the opponent - in opposing blue - was injured early, heavy swelling developing under his eye as the fighters landed punishing blows.
The challenger, 27, connected with strong blows but the champion, 34, matched the intensity with powerful upward punches as the pace seldom decreased over the full distance.
Arthur edged the verdict with official scores of draw, close margin and wider gap, but the two athletes were determined and brave, all the qualities their hero Hatton stood for.
