British light heavyweight Buatsi earned a win yet unimpressive beginning to his career under recent management with a points victory over Zach Parker in the Manchester arena.
The Olympic bronze medallist's work rate seemingly secured him a judges' verdict in a competitive ten-round fight at the Manchester venue.
But the challenger landed significant shots, connecting with powerful clean blows in a contest where the styles failed to mesh, with excessive holding spoiling the contest.
The scoring judges had it 96-94 for to the winner, with the final judge a even score.
"It wasn't my finest performance but what do champions do? They win," Buatsi said in the arena as he was greeted with boos from the crowd.
The British fighter got back to winning after his initial pro loss - an epic battle with his previous opponent in last winter - to secure a twentieth professional win.
Several boxing experts thought Parker, 31, deserved the win but the British boxer experienced the second setback of his 28-fight professional journey.
Buatsi Earns Win in Slow Encounter
Buatsi's progress has stalled in the past few years through management issues and extended periods of inactivity.
Once tipped as the next star of British boxing, he now finds himself trying to fulfil that early promise - maybe in what seems like a ultimate opportunity - under recent support.
He opened tentatively, with neither fighter prepared to overcommit in a cagey opening few rounds.
The challenger, whose single earlier setback came at super-middleweight against his former opponent in 2022 after breaking his hand during the bout, was participating in his second fight at light heavyweight.
By the middle rounds, the underdog had made it competitive, making life awkward for Buatsi, who worked behind a tight guard to barely take the better rounds.
The spectators' acceptance wore thin because of frequent holding, with the challenger slipping to the canvas various instances during close exchanges.
Parker closed well, but many rounds were hard to judge. Nevertheless, previous titleholder the boxing analyst - providing analysis for Dazn - had it particularly wide for the challenger, scoring for Buatsi just one round.
The victor advances, but with the likes of power puncher David Benavidez, and Russian star Dmitry Bivol ruling the division, the path to championship success - based on this performance - still seems difficult.
Ricky Hatton Homage Fuels Local Rivalry Fight
In the co-main event, Lyndon Arthur beat Bradley Rea by divided decision in a terrific Manchester vs Manchester fight to capture the continental championship.
The arena became quiet for a deeply poignant memorial before the fight as a bell ceremony tolled in remembrance of the city's native Hatton, who died aged 46 in recently.
It was the initial significant broadcast fight night in the city since Hatton's death. As the final chime disappeared, the silence gave way to a roar of "there's only one Ricky Hatton".
The competition during the bout reflected the sentiment. Arthur was knocked down by a significant blow flush on the jaw in the early round, getting up unsteadily to his position on the eight count.
But the red-colored shorts of Arthur soon came forward again. From the other corner, the opponent - in competitive blue - was injured quickly, heavy swelling forming under his orbital area as the fighters landed punishing blows.
Rea, twenty-seven, connected with strong blows but the champion, 34, responded in kind with effective uppercuts as the intensity rarely dropped over 12 rounds.
Arthur edged the verdict with scoring tallies of draw, narrow lead and wider gap, but each competitor were determined and courageous, exactly what their hero the legend represented.
