British light-heavyweight Buatsi secured a victory yet unimpressive start to his career under fresh promotional backing with a decision win over Zach Parker in the Manchester arena.
The Olympic medal winner's activity level likely gained him a judges' verdict in a competitive 10-round bout at the boxing arena.
But the challenger found success, connecting with powerful individual punches in a contest where the styles failed to mesh, with constant grabbing spoiling the fight.
The scoring judges had it 96-94 to the winner, with the remaining official a 95-95 draw.
"It wasn't my best showing but how do champions respond? They prevail," the victor commented in the arena as he was met by negative reactions from the spectators.
The Londoner bounced back after his maiden career setback - an epic battle with Callum Smith in last winter - to claim a twentieth professional win.
Several boxing experts thought the challenger, thirty-one, deserved the decision but the contender experienced the second setback of his 28-match career.
The Champion Claims Triumph in Uneventful Match
The fighter's advancement has plateaued in the past few years through promotional disputes and extended periods of inactivity.
Previously predicted as the future of the British fight scene, he now finds himself trying to fulfil that early promise - perhaps in what feels like a last chance - under recent support.
He started carefully, with neither fighter prepared to overcommit in a cagey early stages.
Parker, whose sole prior loss came at the lower weight class against John Ryder in two years ago after damaging his hand in the contest, was making just his second appearance at light-heavyweight.
By the middle rounds, Parker had stayed in contention, creating difficulties for the favorite, who utilized a protective stance to barely take the cleaner periods.
The crowd's patience decreased during constant clinching, with the challenger falling to the floor various instances during close exchanges.
Parker closed well, but multiple periods were difficult to score. Nevertheless, previous titleholder the boxing analyst - commentating on the broadcast network - had it significantly in favor for Parker, scoring for Buatsi just only one stanza.
Buatsi moves on, but with the likes of heavy hitter Benavidez, and Russian champion Dmitry Bivol ruling the division, the road to world glory - judging by this showing - still seems difficult.
Ricky Hatton Memorial Motivates Manchester Derby Contest
In the supporting bout, Lyndon Arthur beat Rea by divided decision in a outstanding all-Manchester fight to secure the European light-heavyweight title.
The stadium fell silent for a deeply poignant memorial prior to the bout as a bell ceremony sounded in memory of local hero Hatton, who succumbed at age 46 in last month.
It was the initial significant broadcast fight night in the city since the passing of Hatton. As the last bell faded, the stillness became a roar of "there's just one Ricky Hatton".
The competition within the ring matched the feeling. The eventual winner was floored by a left hook directly to the face in the initial stage, standing uncertainly to his footing on the referee's count.
But the red-colored attire of Arthur soon advanced again. From the other corner, the opponent - in competitive blue - was injured soon, significant bruising appearing under his eye as the duo landed powerful shots.
Rea, 27, landed power punches but Arthur, thirty-four, fought fire with fire with powerful upward punches as the intensity hardly diminished over the full distance.
Arthur edged the decision with judges scorecards of 114-114, 115-113 and wider gap, but each competitor were persistent and courageous, all the qualities their inspiration Hatton represented.
