UK light-heavyweight Buatsi secured a victory yet unimpressive beginning to life under recent management with a unanimous decision over Zach Parker in Manchester.
The Olympic medal winner's activity level appeared to earn him a split decision in a tight 10-round bout at the boxing arena.
But Parker had his moments, connecting with powerful single shots in a contest where the techniques failed to mesh, with constant grabbing marring the action.
The scoring judges scored it 96-94 for to Buatsi, with the third a 95-95 draw.
"It wasn't my finest display but how do champions respond? They prevail," the victor said in the ringside as he was met by boos from the audience.
The British fighter returned to winning ways after his first professional defeat - an memorable fight with his previous opponent in February - to secure a 20th pro success.
Various analysts felt the challenger, thirty-one, should have been awarded the win but the contender endured the second loss of his 28-match career.
Buatsi Earns Victory in Slow Affair
Buatsi's progress has stalled in recent times through contract problems and extended periods of inactivity.
Previously predicted as the rising talent of British boxing, he now finds himself trying to achieve expectations - maybe in what feels like a last chance - under fresh management.
He began cautiously, with both competitors willing to be aggressive in a cagey opening few rounds.
The challenger, whose single earlier setback came at the lower weight class against John Ryder in 2022 after breaking his hand mid-fight, was competing in only his second appearance at light heavyweight.
By the halfway stage, the underdog had kept it close, making life awkward for the favorite, who worked behind a protective stance to edge the cleaner stanzas.
The crowd's patience wore thin amid constant clinching, with Parker falling to the floor multiple occasions during close exchanges.
Parker closed well, but many rounds 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.
Buatsi advances, but with the caliber of power puncher Benavidez, and Russian star Dmitry Bivol ruling the division, the path to championship success - judging by this showing - still appears challenging.
Hatton Memorial Inspires All-Manchester Battle
In the supporting bout, Arthur defeated Bradley Rea by close verdict in a excellent local rivalry contest to secure the European light-heavyweight championship.
The venue fell silent for a extremely emotional memorial before the fight as ten bells sounded in remembrance of Manchester's own Hatton, who succumbed aged 46 in last month.
It was the premier televised fight night in the city since the passing of Hatton. As the concluding sound ended, the stillness gave way to a shout of "there's just one Ricky Hatton".
The action within the ring equaled the sentiment. The eventual winner was sent to the canvas by a left hook directly to the jaw in the second round, standing uncertainly to his feet on the eight count.
But the Manchester United-red attire of the fighter soon advanced again. On the opposite side, the opponent - in opposing blue - was marked up soon, noticeable damage developing under his face as the pair exchanged punishing blows.
The challenger, 27, connected with strong blows but the champion, thirty-four, matched the intensity with stinging uppercuts as the intensity seldom decreased over 12 rounds.
Arthur barely secured the result with official scores of 114-114, close margin and wider gap, but both fighters were determined and full of heart, exactly what their inspiration the legend stood for.
