UK light heavyweight Buatsi made a winning yet disappointing start to his career under new promoters with a unanimous decision over Zach Parker in the Manchester arena.
The Olympic bronze medallist's work rate likely gained him a split decision in a close ten-round bout at the boxing arena.
But Parker had his moments, landing some telling individual punches in a contest where the approaches failed to mesh, with constant grabbing marring the action.
The scoring judges had it 96-94 for to the winner, with the third a even score.
"It wasn't my best showing but how do champions respond? They succeed," Buatsi said in the arena as he was greeted with negative reactions from the audience.
The British fighter got back to winning after his initial pro loss - an thrilling contest with Callum Smith in last winter - to earn a 20th pro success.
Some ringside observers thought Parker, thirty-one, merited the win but the Derbyshire fighter suffered the second setback of his 28-fight career.
Buatsi Earns Win in Uneventful Match
His career development has plateaued in recent times through contract problems and extended periods of lack of fights.
Earlier forecast as the rising talent of the British fight scene, he now stands trying to realize his potential - maybe in what feels like a last chance - under recent support.
He opened tentatively, with neither fighter prepared to overcommit in a tentative early stages.
Parker, whose single earlier setback came at super-middleweight against John Ryder in 2022 after breaking his hand in the contest, was participating in his second fight at light-heavyweight.
By the middle rounds, Parker had made it competitive, creating difficulties for Buatsi, who utilized a tight guard to barely take the more effective rounds.
The crowd's patience wore thin because of constant clinching, with Parker falling to the floor several times during close exchanges.
Parker finished the stronger, but many rounds were hard to judge. Nevertheless, ex-champion the boxing analyst - providing analysis for the broadcast network - had it particularly wide for Parker, scoring for Buatsi just a single round.
The victor advances, but with the likes of hard hitter David Benavidez, and Russian star Bivol ruling the division, the journey to titles - judging by this showing - still seems difficult.
Hatton Memorial Motivates Manchester Derby Battle
In the secondary fight, Lyndon Arthur beat Rea by divided decision in a excellent local rivalry contest to capture the continental championship.
The stadium fell silent for a deeply poignant tribute ahead of the contest as 10 bells tolled in memory of the city's native Hatton, who died 46 years old in last month.
It was the first major televised fight night in the city since Hatton's passing. As the last bell faded, the quiet gave way to a shout of "only one Hatton".
The action within the ring reflected the sentiment. The eventual winner was sent to the canvas by a significant blow flush on the face in the second round, standing uncertainly to his footing on the eight count.
But the traditional red shorts of Arthur soon came forward again. From the other corner, the opponent - in competitive blue - was marked up early, noticeable damage forming under his eye as the duo landed hard punches.
The challenger, twenty-seven, landed power punches but Arthur, thirty-four, responded in kind with effective uppercuts as the pace seldom decreased over twelve rounds.
Arthur narrowly won the result with judges scorecards of draw, 115-113 and clearer margin, but each competitor were relentless and full of heart, everything their idol Hatton represented.
