UK light-heavyweight Buatsi made a winning yet disappointing beginning to his career under recent management with a unanimous decision over Zach Parker in the Manchester arena.
The Olympic medal winner's activity level likely gained him a split decision in a close ten-round bout at the Manchester venue.
But Parker had his moments, connecting with powerful individual punches in a contest where the techniques didn't complement each other, with frequent clinching disrupting the fight.
Two judges had it 96-94 for to the winner, with the third a 95-95.
"It wasn't my best display but what defines champions? They succeed," the victor stated in the arena as he was greeted with negative reactions from the audience.
The British fighter returned to winning ways after his initial pro loss - an thrilling contest with his previous opponent in last winter - to claim a 20th pro success.
Various analysts believed Parker, 31, deserved the decision but the British boxer experienced the second setback of his 28-fight career.
Buatsi Earns Win in Slow Encounter
His career development has plateaued in the past few years through management issues and extended periods of inactivity.
Previously predicted as the rising talent of the British fight scene, he now stands trying to fulfil that early promise - perhaps in what appears to be a last chance - under fresh management.
He started carefully, with both competitors prepared to take risks in a cagey opening few rounds.
Parker, whose sole prior loss came at super-middleweight against his former opponent in two years ago after damaging his hand mid-fight, was participating in his second appearance at the higher weight class.
By the halfway stage, the underdog had stayed in contention, making life awkward for Buatsi, who worked behind a tight guard to edge the better rounds.
The audience's tolerance diminished amid constant clinching, with the challenger slipping to the canvas various instances during close exchanges.
The underdog finished the stronger, but many rounds were difficult to score. Although, former world champion Carl Frampton - commentating on the broadcast network - had it particularly wide for Parker, giving Buatsi just a single round.
The victor advances, but with the caliber of power puncher David Benavidez, and Russian star Dmitry Bivol leading the category, the path to championship success - on this evidence - still looks steep.
Hatton Memorial Motivates All-Manchester Fight
In the co-main event, Arthur defeated Bradley Rea by split-decision in a excellent local rivalry fight to capture the European light-heavyweight championship.
The arena fell silent for a extremely emotional tribute prior to the bout as a bell ceremony tolled in memory of the city's native Hatton, who succumbed 46 years old in recently.
It was the first major televised fight night in the location since Hatton's passing. As the final chime disappeared, the quiet gave way to a shout of "there's just one Hatton".
The fighting within the ring equaled the sentiment. Arthur was knocked down by a powerful punch flush on the face in the initial stage, rising shakily to his feet on the referee's count.
But the traditional red equipment of the fighter soon came forward again. From the other corner, Rea - in rival City blue - was marked up soon, heavy swelling appearing under his orbital area as the fighters exchanged powerful shots.
Rea, 27, landed power punches but Arthur, thirty-four, responded in kind with effective uppercuts as the pace hardly diminished over twelve rounds.
The victor barely secured the decision with judges scorecards of draw, 115-113 and clearer margin, but each competitor were determined and brave, all the qualities their idol Hatton represented.
