UK light heavyweight Buatsi earned a win yet unimpressive beginning to life under new promoters with a points victory over Zach Parker in the Manchester arena.
The Olympic bronze medallist's work rate seemingly secured him a split decision in a competitive 10-round bout at the Co-op Live Arena.
But the challenger landed significant shots, landing some telling clean blows in a match where the styles failed to mesh, with excessive holding disrupting the action.
The scoring judges judged it 96-94 in favor to the winner, with the third a 95-95 draw.
"It wasn't my greatest showing but how do champions respond? They win," the victor stated in the ring as he was met by disapproval from the spectators.
The Londoner bounced back after his first professional defeat - an epic battle with Callum Smith in last winter - to earn a 20th pro success.
Some ringside observers felt Parker, thirty-one, merited the win but the contender endured the second setback of his 28-bout professional journey.
Buatsi Earns Win in Uneventful Affair
The fighter's advancement has stalled in recent years through promotional disputes and extended periods of lack of fights.
Previously predicted as the future of UK boxing, he now stands trying to realize his potential - possibly in what appears to be a last chance - under recent support.
He started carefully, with the two boxers ready to be aggressive in a tentative opening few rounds.
Parker, whose only previous defeat came at super middleweight against his former opponent in two years ago after suffering a hand injury during the bout, was making just his second fight at the higher weight class.
By the middle rounds, the underdog had stayed in contention, making life awkward for the favorite, who operated with a protective stance to barely take the more effective stanzas.
The audience's tolerance diminished amid constant clinching, with the challenger slipping to the canvas various instances during close exchanges.
The underdog ended stronger, but multiple periods were difficult to score. Although, former world champion the boxing analyst - working with the broadcast network - had it strongly leaning for Parker, scoring for Buatsi just one round.
The victor progresses, but with the caliber of heavy hitter David Benavidez, and Eastern European fighter Dmitry Bivol ruling the division, the road to world glory - on this evidence - still looks steep.
Hatton Memorial Fuels Local Rivalry Contest
In the supporting bout, Arthur beat Rea by divided decision in a terrific local rivalry contest to secure the continental title.
The stadium became quiet for a profoundly moving memorial ahead of the contest as a bell ceremony sounded in honor of the city's native Hatton, who succumbed aged 46 in recently.
It was the first major televised boxing event in the urban center since the passing of Hatton. As the last bell disappeared, the quiet transitioned to a shout of "only one Hatton".
The competition during the bout equaled the sentiment. Arthur was floored by a powerful punch directly to the chin in the initial stage, standing uncertainly to his position on the eight count.
But the red-colored equipment of the fighter soon pressed ahead again. From the other corner, Rea - in competitive blue - was damaged quickly, noticeable damage appearing under his orbital area as the pair landed hard punches.
The challenger, 27, delivered effective strikes but Arthur, thirty-four, matched the intensity with stinging uppercuts as the action hardly diminished over the full distance.
The victor edged the decision with scoring tallies of draw, narrow lead and clearer margin, but the two athletes were persistent and courageous, all the qualities their idol the legend represented.
