UK light heavyweight Buatsi earned a win yet unimpressive beginning to his career under fresh promotional backing with a unanimous decision over Zach Parker in Manchester.
The Olympic medal winner's punch output seemingly secured him a majority decision in a tight ten-round bout at the Manchester venue.
But the challenger had his moments, connecting with powerful single shots in a contest where the techniques failed to mesh, with constant grabbing disrupting the contest.
Two judges scored it 96-94 in favor to the winner, with the final judge a even score.
"It wasn't my finest performance but what defines champions? They succeed," Buatsi commented in the ringside as he was greeted with disapproval from the audience.
The British fighter got back to winning after his initial pro loss - an memorable fight with Callum Smith in last winter - to claim a 20th pro success.
Several boxing experts felt the challenger, thirty-one, deserved the win but the Derbyshire fighter endured the second setback of his 28-fight professional journey.
Buatsi Claims Win in Slow Encounter
His career development has stalled in recent years through management issues and extended periods of lack of fights.
Previously predicted as the next star of British boxing, he now finds himself trying to achieve expectations - perhaps in what seems like a ultimate opportunity - under recent support.
He opened tentatively, with neither fighter prepared to overcommit in a cagey initial rounds.
The challenger, whose only previous defeat came at super-middleweight against John Ryder in 2022 after damaging his hand in the contest, was making just his second fight at light-heavyweight.
By the fight's midpoint, the underdog had kept it close, causing problems for Buatsi, who operated with a tight guard to edge the better rounds.
The spectators' acceptance wore thin during frequent holding, with the challenger slipping to the canvas several times during grappling.
Parker ended stronger, but multiple periods were hard to judge. Although, former world champion the boxing analyst - working with the broadcast network - had it significantly in favor for the challenger, giving Buatsi just a single round.
Buatsi advances, but with the likes of heavy hitter Benavidez, and Russian champion Bivol leading the category, the road to world glory - judging by this showing - still seems difficult.
Ricky Hatton Homage Motivates Manchester Derby Contest
In the co-main event, Lyndon Arthur beat Rea by close verdict in a outstanding local rivalry contest to win the European light heavyweight title.
The stadium became quiet for a deeply poignant memorial ahead of the contest as 10 bells sounded in remembrance of the city's native Hatton, who died 46 years old in recently.
It was the initial significant broadcast fight night in the urban center since Hatton's death. As the last bell disappeared, the stillness became a shout of "only one Hatton".
The competition within the ring matched the emotion. The eventual winner was floored by a left hook directly to the face in the second round, rising shakily to his footing on the referee's count.
But the Manchester United-red shorts of the fighter soon pressed ahead again. Across the ring, the opponent - in opposing blue - was damaged soon, noticeable damage forming under his face as the fighters landed hard punches.
Rea, twenty-seven, connected with strong blows but Arthur, thirty-four, responded in kind with effective uppercuts as the intensity hardly diminished over twelve rounds.
Arthur narrowly won the verdict with judges scorecards of 114-114, 115-113 and wider gap, but each competitor were persistent and courageous, everything their inspiration the legend embodied.
