British light-heavyweight Buatsi made a winning yet unimpressive debut to life under recent management with a points victory over Zach Parker in Manchester.
The Olympic medal winner's activity level appeared to earn him a majority decision in a close 10-round fight at the Co-op Live Arena.
But Parker found success, landing some telling clean blows in a match where the approaches failed to mesh, with excessive holding spoiling the contest.
Two judges judged it 96-94 to Buatsi, with the remaining official a even score.
"It wasn't my finest performance but what defines champions? They prevail," Buatsi stated in the ringside as he was met by negative reactions from the crowd.
The British fighter returned to winning ways after his first professional defeat - an memorable fight with Callum Smith in February - to claim a twentieth professional win.
Several boxing experts thought the challenger, thirty-one, should have been awarded the win but the contender endured the second defeat of his 28-match career.
The Champion Secures Victory in Uneventful Affair
The fighter's advancement has stalled in recent times through promotional disputes and considerable time of inactivity.
Once tipped as the next star of British boxing, he now stands trying to realize his potential - possibly in what appears to be a final roll of the dice - under new promotional backing.
He began cautiously, with neither fighter willing to overcommit in a calculated initial rounds.
The challenger, whose sole prior loss came at super-middleweight against his former opponent in 2022 after damaging his hand in the contest, was participating in his second fight at light heavyweight.
By the middle rounds, the underdog had made it competitive, creating difficulties for the favorite, who utilized a protective stance to narrowly win the better rounds.
The crowd's patience diminished because of regular grabbing, with Parker going down multiple occasions during clinches.
Parker ended stronger, but many rounds were difficult to score. Nevertheless, ex-champion 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 presence of hard hitter David Benavidez, and Russian champion Bivol dominating the weight class, the road to world glory - based on this performance - still looks steep.
Hatton Tribute Fuels Local Rivalry Fight
In the co-main event, Arthur defeated Bradley Rea by close verdict in a outstanding Manchester vs Manchester battle to secure the European light heavyweight title.
The arena fell silent for a profoundly moving memorial before the fight as ten bells tolled in memory of Manchester's own Hatton, who died 46 years old in recently.
It was the first major televised fight night in the city since the passing of Hatton. As the last bell disappeared, the quiet gave way to a shout of "there's just one Ricky Hatton".
The action during the bout matched the sentiment. The eventual winner was knocked down by a left hook directly to the jaw in the initial stage, standing uncertainly to his footing on the eight count.
But the red-colored equipment of Arthur soon came forward again. Across the ring, the opponent - in rival City blue - was damaged soon, noticeable damage forming under his eye as the pair landed hard punches.
The challenger, twenty-seven, connected with strong blows but the champion, 34, fought fire with fire with stinging uppercuts as the pace hardly diminished over 12 rounds.
Arthur edged the verdict with official scores of draw, narrow lead and wider gap, but each competitor were determined and courageous, all the qualities their hero Hatton embodied.
