UK light heavyweight Buatsi secured a victory yet underwhelming debut to life under recent management with a unanimous decision over Zach Parker in the Manchester arena.
The Olympic medal winner's punch output seemingly secured him a judges' verdict in a tight ten-round fight at the boxing arena.
But the challenger had his moments, connecting with powerful individual punches in a contest where the techniques failed to mesh, with excessive holding disrupting the fight.
Two judges judged it 96-94 in favor to Buatsi, with the final judge a 95-95 draw.
"It wasn't my greatest performance but what defines champions? They win," Buatsi commented in the arena as he was greeted with negative reactions from the crowd.
The Londoner bounced back after his first professional defeat - an epic battle with his previous opponent in February - to secure a 20th pro success.
Several boxing experts believed the challenger, thirty-one, deserved the win but the Derbyshire fighter experienced the second setback of his 28-fight career.
The Champion Earns Win in Uneventful Affair
His career development has plateaued in recent times through management issues and considerable time of inactivity.
Once tipped as the rising talent of British boxing, he now stands trying to fulfil that early promise - maybe in what appears to be a final roll of the dice - under recent support.
He opened tentatively, with neither fighter ready to take risks in a calculated opening few rounds.
Parker, whose sole prior loss came at super-middleweight against his former opponent in two years ago after damaging his hand in the contest, was making just his second fight at light-heavyweight.
By the halfway stage, Parker had kept it close, making life awkward for the favorite, who operated with a tight guard to edge the better rounds.
The crowd's patience wore thin amid regular grabbing, with Parker going down several times during close exchanges.
Parker ended stronger, but many rounds were challenging to assess. Although, 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 advances, but with the likes of hard hitter Benavidez, and Russian champion Bivol ruling the division, the journey to titles - based on this performance - still appears challenging.
Hatton Homage Inspires Manchester Derby Fight
In the secondary fight, Lyndon Arthur defeated Rea by close verdict in a outstanding Manchester vs Manchester fight to capture the continental championship.
The stadium fell silent for a profoundly moving memorial prior to the bout as ten bells tolled in honor of the city's native Hatton, who passed away at age 46 in September.
It was the initial significant broadcast match card in the urban center since Hatton's passing. As the concluding sound disappeared, the silence gave way to a chant of "only one Ricky Hatton".
The action within the ring reflected the emotion. Arthur was floored by a significant blow flush on the jaw in the early round, rising shakily to his position on the referee's count.
But the Manchester United-red equipment of the fighter soon pressed ahead again. Across the ring, Rea - in rival City blue - was injured early, heavy swelling appearing under his orbital area as the fighters landed powerful shots.
Rea, 27, landed power punches but the champion, thirty-four, responded in kind with stinging uppercuts as the pace seldom decreased over twelve rounds.
Arthur narrowly won the result with judges scorecards of even score, 115-113 and 115-112, but each competitor were persistent and courageous, exactly what their idol the legend embodied.
