UK light heavyweight Buatsi made a winning yet disappointing beginning to life under recent management with a decision win over Zach Parker in the Manchester arena.
The Olympic bronze medallist's activity level appeared to earn him a judges' verdict in a tight ten-round bout at the Manchester venue.
But Parker had his moments, connecting with powerful clean blows in a fight where the techniques didn't complement each other, with frequent clinching marring the action.
The scoring judges had it 96-94 to Buatsi, with the remaining official a 95-95.
"It wasn't my best showing but what defines champions? They win," the victor said in the ringside as he was met by disapproval from the audience.
The British fighter got back to winning after his initial pro loss - an epic battle with his previous opponent in last winter - to claim a twentieth professional win.
Some ringside observers felt the challenger, thirty-one, merited the decision but the British boxer suffered the second setback of his 28-fight professional journey.
The Champion Secures Win in Dull Encounter
The fighter's advancement has slowed in recent times through contract problems and considerable time of inactivity.
Previously predicted as the next star of British boxing, he now is positioned trying to realize his potential - possibly in what seems like a last chance - under new promotional backing.
He opened tentatively, with neither fighter prepared to be aggressive in a calculated opening few rounds.
The challenger, whose sole prior loss came at the lower weight class against his former opponent in two years ago after breaking his hand in the contest, was competing in only his second fight at light-heavyweight.
By the middle rounds, Parker had made it competitive, creating difficulties for Buatsi, who utilized a solid defense to edge the better rounds.
The spectators' acceptance diminished amid constant clinching, with the challenger going down various instances during close exchanges.
Parker ended stronger, but multiple periods were difficult to score. However, ex-champion Carl Frampton - commentating on the broadcast network - had it particularly wide for the challenger, scoring for Buatsi just only one stanza.
Buatsi advances, but with the likes of heavy hitter David Benavidez, and Russian champion Bivol dominating the weight class, the path to championship success - judging by this showing - still seems difficult.
Hatton Homage Fuels Local Rivalry Contest
In the supporting bout, Lyndon Arthur defeated Rea by close verdict in a outstanding Manchester vs Manchester fight to secure the European light heavyweight championship.
The stadium became quiet for a profoundly moving memorial prior to the bout as ten bells rang in memory of Manchester's own Hatton, who died at age 46 in September.
It was the initial significant broadcast match card in the urban center since Hatton's death. As the last bell faded, the quiet gave way to a chant of "there's only one Ricky Hatton".
The competition inside the ropes matched the emotion. Arthur was floored by a powerful punch squarely on the chin in the early round, standing uncertainly to his footing on the referee's count.
But the red-colored shorts of the fighter soon pressed ahead again. From the other corner, the opponent - in rival City blue - was marked up early, significant bruising appearing under his face as the duo landed hard punches.
Rea, twenty-seven, connected with strong blows but Arthur, thirty-four, responded in kind with powerful upward punches as the action seldom decreased over twelve rounds.
The victor narrowly won the result with scoring tallies of even score, 115-113 and 115-112, but each competitor were persistent and full of heart, all the qualities their idol the legend embodied.
