UK light heavyweight Buatsi made a winning yet underwhelming beginning to life under recent management with a decision win over Zach Parker in Manchester.
The Olympic medal winner's work rate seemingly secured him a judges' verdict 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 didn't complement each other, with constant grabbing marring the contest.
The officials had it 96-94 for to the winner, with the final judge a even score.
"It wasn't my best display but what defines champions? They win," Buatsi said in the ring as he was greeted with boos from the crowd.
The British fighter got back to winning after his initial pro loss - an memorable fight with Callum Smith in February - to claim a twentieth professional win.
Various analysts felt the challenger, thirty-one, merited the win but the British boxer endured the second setback of his 28-fight career.
Buatsi Secures Triumph in Dull Encounter
The fighter's advancement has plateaued in the past few years through promotional disputes and extended periods of inactivity.
Once tipped as the rising talent of British boxing, he now is positioned trying to realize his potential - possibly in what feels like a ultimate opportunity - under recent support.
He began cautiously, with both competitors willing to take risks in a calculated opening few rounds.
Parker, whose single earlier setback came at the lower weight class against John Ryder in two years ago after damaging his hand mid-fight, was making just his second bout at the higher weight class.
By the fight's midpoint, the underdog had made it competitive, creating difficulties for Buatsi, who worked behind a tight guard to barely take the cleaner rounds.
The crowd's patience diminished because of constant clinching, with the challenger going down multiple occasions during grappling.
Parker finished the stronger, but several stanzas were challenging to assess. Nevertheless, previous titleholder the boxing analyst - working with the broadcast network - had it particularly wide for Parker, scoring for Buatsi just only one stanza.
The victor moves on, but with the caliber of heavy hitter David Benavidez, and Russian star Dmitry Bivol leading the category, the path to championship success - on this evidence - still appears challenging.
Hatton Memorial Fuels Local Rivalry Contest
In the supporting bout, Arthur beat Bradley Rea by split-decision in a outstanding Manchester vs Manchester battle to win the continental belt.
The arena grew hushed for a extremely emotional homage prior to the bout as ten bells rang in honor of the city's native Hatton, who died at age 46 in September.
It was the first major televised fight night in the city since Hatton's death. As the final chime faded, the silence became a chant of "there's just one Hatton".
The action inside the ropes reflected the sentiment. The eventual winner was floored by a significant blow directly to the jaw in the second round, standing uncertainly to his feet on the referee's count.
But the Manchester United-red equipment of the fighter soon pressed ahead again. Across the ring, the opponent - in rival City blue - was damaged soon, noticeable damage forming under his eye as the pair exchanged hard punches.
The challenger, twenty-seven, connected with strong blows but the champion, 34, matched the intensity with stinging uppercuts as the pace seldom decreased over twelve rounds.
The victor edged the result with judges scorecards of 114-114, close margin and 115-112, but both fighters were determined and courageous, exactly what their idol Hatton embodied.
